The precise date of the Council of Serdica is so important because it is essential for establishing the chronology of numerous events in fourth-century Christianity, and thus for reconstructing its overall history and developments. Unfortunately, this date has been under debate for nearly two centuries. Traditionally, the council was dated to 347 C.E., but discoveries in the 18th and 19th centuries led scholars to favor first 344 and then 343. In the early 20th century, Eduard Schwartz inaugurated a new stage in the debate when he argued for 342. In his wake, most French, Italian, and English-speaking scholars argued for 343, whereas most German-speaking scholars followed Schwartz's authority and endorsed 342. In 1974, Marcel Richard advanced a novel argument in favor in 342 that appeared to cement this date for its advocates. Recently, however, 343 appears to be the preferred date even in German scholarship. After more than a century of debate, it seems, a consensus has been reached. This essay offers the most comprehensive reassessment of this debate to date to see if it really should be considered concluded. It re-examines all the evidence and all the arguments made in support of one date or another, in particular those of Schwartz and Richard, and argues that the case for the Council of Serdica's having been held in the autumn of 343 should be considered conclusive; thus, the lengthy debate can rightly be closed.

The Council of Serdica has gone down in history as a “debacle,”1 a “disaster,”2 a “fiasco.”3 Instigated by Emperors Constans and Constantius to resolve tensions between western and eastern bishops, it only exacerbated them and pushed relations between the two groups of bishops to the breaking point.4 The multifaceted debates catalyzed by the dispute between Alexander and Arius in Alexandria in the early 320s increasingly put a strain on relations between eastern and western bishops, and they became even more fraught by the proceedings of two antagonistic councils in 341, the first in Antioch and the second in reaction to it in Rome. In addition to theological differences and mutual suspicions of heterodoxy, at issue were the contested charges against Athanasius of Alexandria and Marcellus of Ancyra, whom recent eastern councils had deposed, respectively, for malfeasance and for heresy.

To resolve these problems, Constans proposed to Constantius that a joint council be held, and upon agreement each emperor issued summons to the bishops in his domains. Nearly one-hundred western bishops and approximately seventy-five eastern bishops travelled to Serdica (modern-day Sofia in Bulgaria), a location as neutral as possible since it was in Constans’ realms but on the border between the two halves of the Roman Empire ruled by himself and Constantius. When the eastern bishops arrived, however, they refused to join with the western bishops because the latter had granted Athanasius, Marcellus, and other deposed bishops full participation in the conciliar proceedings, in spite of the fact that they “had been tried, condemned, and deposed by regularly convened and ordered eastern councils.”5 As the eastern bishops considered these deposed bishops barred from involvement, they demanded that the western bishops as a whole separate themselves from them before the joint council began. The western bishops protested that the deposed bishops had a right to be seated until their cases had been adjudicated. At stake in the refusal was the eastern bishops’ conviction that no western council, not even a Council of Rome presided over by the Bishop of Rome, could review and overturn the decisions of eastern councils; the eastern bishops were thus asserting their ecclesiastical independence against encroachment by the western church.

Negotiations broke down, and soon the eastern bishops withdrew to Philippopolis (modern-day Plovdiv), a city to the southeast of Serdica that was securely within the domains of Constantius and where they had assembled prior to the council before traveling en bloc to Serdica. Here they released an encyclical letter. In their absence, the western bishops carried on with the work of the council in Serdica, exonerating Athanasius and Marcellus and promulgating a host of documents. Before dispersing to their sees, each side excommunicated the leading bishops of other side, accusing them of heresy (the western bishops were said to be “Sabellians,” the eastern bishops “Arians”). This was essentially the first formal break between the eastern and western churches and the initial step on the path to the Great Schism that still troubles us today. Furthermore, the ecclesiastical canons issued by the western bishops included the so-called “appeal canons,” which provided “recourse to assistance by the bishop of Rome for bishops who claimed unfair treatment from judgement by their peers.” These canons “exerted an undeniable influence upon the subsequent jurisdictional enhancement of the institutional papacy” to the long-term detriment of communion between eastern and western churches.6 Thus, as Edward Gibbon said long ago, the Council of Serdica “reveals the first symptoms of discord and schism between the Greek and Latin churches, which were separated by the accidental difference of faith, and the permanent distinction of language”—a sentiment that has been repeated ever since in the historiography on the council.7 

The course of the Council of Serdica can be adequately reconstructed from the dossier it produced as well as from accounts by participants such as Athanasius, but the chronological indicators in these same texts are insufficient for establishing its precise date or length. Establishing the exact date is not simply a matter of antiquarian interest. As the work of scholars such as T. D. Barnes has repeatedly demonstrated, accurate chronography matters tremendously. The date assigned to the Council of Serdica affects how one understands and interprets numerous theological, ecclesio-political, and imperial developments in the fourth century. For instance, the Council of Serdica is the result of rare cooperative effort between Constans and Constantius, and being precise about when it took place helps us better understand the history of the complicated relationship between these two emperors.8 Another example: the nadir reached at the Council led, in its aftermath, to attempts at rapprochement by western and eastern bishops, a program which, through many twists and turns, reached its apogee, arguably, in the imperial endorsement of Nicene theology at the Council of Constantinople in 381; accordingly, knowing the precise date of the Council of Serdica is essential for understanding the initial stages of this long trajectory.9 Furthermore, the significance of the Council of Serdica occasionally led late antique authors to speak of other events as so many years before or after it; accordingly, being able to establish its date with greater certitude enables other dates to be established more securely. For example, a document issued by the eastern bishops at Serdica mentions that Asclepas of Gaza was deposed seventeen years before the Council.10 Since the deposition of Asclepas is the terminus ante quem for the deposition of Eustathius of Antioch, the correct date of the Council of Serdica is of crucial importance for understanding the events around Eustathius that led to his deposition and thus the shifting nature of ecclesio-political history in the late 320s.11 Like textual criticism, then, chronography is absolutely fundamental for the wide variety of higher studies that depend upon it.

Few dates in the fourth century have been as heavily contested and have generated as much scholarship as the date of the Council of Serdica. Traditionally it was held to have occurred in 347 on the basis of evidence from Socrates and Sozomen.12 This date should have been suspect, however, since long-available Athanasian evidence did not support it.13 The traditional date was finally jettisoned after the discovery of the Historia acephala in the 18th century.14 Soon afterwards, J. D. Mansi published an influential study that, based on the then-available evidence, concluded that the council had been held in 344.15 After the discovery of the ancient Syriac translation of the Festal Letters of Athanasius and their Index in the 19th century,16 a date of 343 for the council won the support of most scholars, until Eduard Schwartz proposed a date of 342 in a series of publications starting in 1904.17 Schwartz's arguments were worked out with great care and his customary erudition, and involved identifying and discussing every available piece of evidence, often bringing new information to bear upon the question. Schwartz's thesis, however, sparked an immediate defense of the 343 date by Friedrich Loofs and Otto Seeck, thereby setting the parameters and terms for all subsequent debate.18 The question was afterwards centered on whether the council had been held in 342 or 343. Most French, Italian, and English-speaking scholars have argued for a date of 343.19 In the wake of Schwartz, most German-speaking scholars favored a 342 date for the council.20 In recent years, however, 343 appears to have become the generally recognized date even in German scholarship.21 At long last, it seems, a consensus on the issue has been reached.

It is high time, then, for a full historiographical review and reassessment of this debate to see if it really should be considered concluded. In over a century of scholarship, discussions of the pertinent evidence have often (though not always) been made in passing in the service of other interests, hidden away in footnotes and appendices, and in a more or less compressed manner. As yet there has not been a comprehensive survey in English of all the evidence and all the arguments made in support of one date or another, a situation which this present essay seeks to remedy. I contend that the case for the Council of Serdica's having been held in the autumn of 343 is conclusive; thus, the lengthy debate can rightly be closed. In this historiographical review and reassessment I limit myself to engagement with those scholars who have discussed the date of the council in the most detail. On the side of 342 this includes Schwartz, William Telfer, Marcel Richard (who is notable for offering a truly new argument for 342 in addition to that of Schwartz, and one that found considerable support), Hanns Christoff Brennecke, T. G. Elliott, and Jörg Ulrich.22 The main proponents of 343 are Alfred Feder, Jacques Zeiller, Victor C. De Clerq, Hamilton Hess, Charles Pietri, T. D. Barnes, Leslie W. Barnard, Richard Burgess, and Sara Parvis.23 For the most part I leave aside those who have merely adopted or approvingly cited the conclusions of others.24 Three tasks are required to demonstrate that the arguments for 343 are conclusive and thus that the debate over the date of the Council of Serdica can be considered closed: first, to explain why Schwartz's argument for dating the council to 342 has come to be seen as resting upon a very shaky foundation; second, to show the tenuousness of Richard's argument for 342; and third, to rehearse the main arguments in favor of 343, which, as T. D. Barnes once said, “have lost none of their cogency.”25 

It is obvious that the Council of Serdica took place during Athanasius's second exile. From the Historia acephala and Festal Index we learn that on 16 March 339 an attempt was made to arrest Athanasius, on 17 March he went into hiding in Alexandria, on 22 March his replacement Gregory entered the city, on 16 April Athanasius fled Alexandria, and in June or July 339 he arrived in Rome.26 His second exile ended when he returned to Alexandria on 21 October 346.27 Furthermore, we know from the Festal Index that Athanasius celebrated three Easters after the council before returning to Alexandria.28 These have to be the Easters of 344 (spent at Naissus), 345 (at Aquileia), and 346 (at an unknown location). Therefore, the council must have been held before Easter 344 (15 April).29 According to the evidence enumerated so far, then, the Council of Serdica took place between the summer of 339 and early April 344.


Other evidence can be marshalled to narrow this range of dates even further. In Historia Arianorum 20–21, Athanasius reports that upon the conclusion of the Council of Serdica, the western bishops sent a delegation to the court of Constantius in Antioch seeking his consent to the council's decree that deposed bishops be restored to their sees. The delegation consisted of two bishops, Vincentius of Capua and Euphrates of Agrippina (i.e. Cologne). Athanasius relates that they also carried a letter from Constans to Constantius in support of the council's request. According to Theodoret, the delegates travelled with a military escort led by “general Salianus,” who has been identified as Flavius Salia, magister equitum under Constans from 344 to 348.30 They arrived in Antioch around Easter (Athanasius does not specify the year) and soon thereafter a scandalous plot was hatched against the delegates, orchestrated by Stephen of Antioch. It backfired, however, leading to Stephen's deposition and his replacement by Leontius. Athanasius reports that “a short time” after this (ὀλίγον τι), Constantius ordered the release of Athanasian presbyters and deacons who had been banished to Armenia and also wrote to the Alexandrian church that supporters of Athanasius should no longer be persecuted.31 And “then about ten months later” (εἶτα μετὰ μῆνάς που δέκα) the interloper Gregory of Alexandria died.32 Since we can pinpoint the date of Gregory's death to 26 June 345,33 Constantius must have written to the Alexandrians around August or September 344 and accordingly the delegates must have arrived in Antioch around Easter 344 (15 April). If it is assumed that the delegation was sent when the council ended and went directly to Antioch, then the arrival in mid-April 344 points to a conclusion of the council anywhere between a little more than two weeks earlier or about two months earlier, depending on the mode and rate of travel (see Map 1).34 This means that the delegation departed Serdica at the latest between mid-February and late-March 344, and that the council had been held shortly before this.35 

Map 1.

Serdica to Antioch. The Fastest Journey in Winter or Spring.

Map 1.

Serdica to Antioch. The Fastest Journey in Winter or Spring.

Those who advocate a 342 date for the Council of Serdica have two options for interpreting this same evidence: they must either place the arrival of the delegation in Antioch at Easter 343 and explicate why the ὀλίγον τι of Athanasius indicated such a long time, or explain why there was such a protracted period between the council's conclusion at the end of 342 and the arrival of the delegation in Antioch over a year later at Easter 344. All the arguments made in favor of either interpretation, however, have failed to persuade. Schwartz (followed by Opitz and Lietzmann) took the first option.36 He dated the arrival of the delegation to Easter 343 (27 March), thereby suggesting that the ὀλίγον τι of Athanasius lasted 18 months, to September 344 when Constantius wrote the Alexandrian church. But the notion that an ὀλίγον τι could indicate a span of 18 months stretches the limits of plausibility. Athanasius indicates that it was the events stirred up by Stephen in Antioch that motivated Constantius to grant clemency to the supporters of Athanasius. So it seems unlikely that Constantius would wait 18 months after the deposition of Stephan to grant it. Even Richard, Brennecke, and Ulrich, fellow advocates of 342, rejected this reconstruction of Schwartz and Lietzmann, placing the arrival of the delegation at Easter 344 for the reasons outlined above.37 Richard took the second option, and in this he was followed by Elliott. He denied that the delegates were sent by the Council of Serdica directly after it, suggesting that Athanasius excessively simplified his narrative in Historia Arianorum 20. He preferred the narrative of Theodoret, who attributed the decision to send delegates to Constans.38 Richard found it unlikely that the delegates would have accepted a new voyage after being away from their home dioceses during the council, and he added that the delegates would have been disinclined to go on a long journey because at the time, given “the violent passions unleashed by the council,” it was a fool's errand with practically no chance of success.39 Accordingly, Richard posited a delay of 18 months between the conclusion of the council in late 342 and the sending of the delegation by Constans 18 months later in calmer times, arriving in Antioch around Easter 344.40 It seems unlikely, however, that Constans would have waited so long to communicate with his brother about the decisions of the Council of Serdica; Richard has provided no concrete reasons for such a long delay.41 Ulrich suggested that the journey from Serdica to Antioch actually took 18 months because the roads were clogged with Constantius's soldiers involved in the Persian campaign.42 This seems implausible too.43 

The argument of Richard raises the important question of whether the accounts of Athanasius and Theodoret can be reconciled. According to Theodoret, Constans decided to send a delegation as a direct consequence of hearing the report about the council. According to Athanasius, the delegates carried a letter from the council to Constantius and another from Constans to the same. The accounts, when taken together, thus appear to indicate some sort of co-ordination between the bishops at Serdica and the emperor. We may imagine a scenario like this: at the conclusion of the council, the bishops sent a messenger to inform Constans of its proceedings,44 and then Constans sent a message back ordering them to send a delegation to Constantius, along with his own letter to his brother. A further complication is that Euphrates of Agrippina is not on the list of bishops who attended the Council of Serdica, in spite of Theodoret's assumption (and Athanasius's implication) that he had.45 Parvis has speculated that Euphrates was Constans’ own messenger to the bishops at Serdica in reply to their report about the proceedings of the council, and that Constans had ordered him to join with one of the bishops who had attended the council to travel eastward.46 Even if this was not the precise scenario, it is reasonable to assume that there were communications between the emperor and the council at its conclusion before the delegates departed for the East. The question is how long these communications would have taken. At the end of 343 Constans was in Trier,47 and the journey from Serdica to Trier would have taken approximately a month (see Map 2).48 And so, between two and four months would have been needed for the communications between the bishops and the emperor (that is, a round trip) before the delegation could have departed.49 If the delegation departed for Antioch at the latest between mid-February and late-March 344, then the council must have concluded at the latest between mid October 343 and late January 344.50 

Map 2.

Serdica to Trier. The Fastest Journey in Winter or Spring.

Map 2.

Serdica to Trier. The Fastest Journey in Winter or Spring.


Athanasius's Apologia ad Constantium 4 provides another piece of relevant information to narrow the range of possible dates for the Council of Serdica. Here Athanasius reports that “after three years had passed, in the fourth year,” he was summoned by Constans to Milan and learned of the emperor's plans to call the council.51 Most scholars have assumed that Athanasius was counting from the start of his second exile, 17 March 339, when he went into hiding in Alexandria, or 16 April 339, when he left Alexandria, and accordingly supposed that Constans’ summons reached Athanasius after mid-March to mid-April 342. Thus this became the terminus post quem for the council. Some scholars, however, have suggested that the phrase “after three years had passed, in the fourth year” is ambiguous. Parvis pointed out that Athanasius could be counting from his departure from Alexandria, from his arrival in Rome (June or July 339), or even from his initial exchange of letters with Constans in early 338.52 If the last of these, Athanasius could have met with Constans in Milan at some point in 341 (and there is independent evidence for Constans’ presence in Milan on 25 June 341).53 This of course would have left plenty of time for the Council of Serdica to be held in 342, but it breaks the limits of plausibility that Athanasius would have started counting from his initial letter exchange with Constans. The plain sense of the passage is that Athanasius is counting from his departure from Alexandria—that is, around mid-April 339.54 Accordingly, the Council of Serdica took place sometime after mid-April 342.

But how long after? Advocates of the 343 date have argued that ample time had to be allowed for Constantius to reply to Constans and for sending the official summons to the council, as well as for the known movements before the council of Athanasius (from Rome to Milan to Gaul to Serdica) and Constans (from Milan to Bononia to Britain to Trier).55 Nothing, according to this argument, precluded the meeting of Athanasius and Constans in Milan from having taken place several months into the fourth year of his exile—that is, through early winter 342.56 Accordingly, too much would have needed to have happened in too short a span of time for the Council of Serdica to have been held in the autumn of 342.

There are several other indications that the council is more likely to have been held in the autumn of 343. There is independent attestation for Constans’ presence in Milan on 4 December 342 and in Trier on 30 June 343, and Barnes and others have dated his first meeting with Athanasius in Milan to the autumn of 342 and posited a second in Trier in the summer of 343.57 If the date of the meeting in Milan is correct, then the Council of Serdica could not have been held in the autumn of 342. As for the second meeting, De Clerq, Barnes, and others interpreted Athanasius as saying that when he went to Gaul after being summoned by Constans, he met the emperor there in Trier. From Gaul Athanasius reports that he travelled with Ossius to Serdica. If this second meeting took place, then the council would have had to have assembled after the summer of 343.58 Furthermore, it is not known precisely when the official summons to the council was sent by the bishops, but based on the summons of other councils it seems that they would have been sent at least six months before its assembly.59 If the summons was only sent out after Constans met with Athanasius (as Hess assumed), then the council could not have been held in the autumn of 342. Only if it was sent out considerably before this would it have been possible for the eastern bishops to reach Serdica in time for a council in the autumn of 342.60 Finally, Socrates records that “a year and half elapsed” between the summoning of the council and its assembling.61 If this is accurate, then it seems impossible for the council to have assembled by the end of the 342. It seems more likely, therefore, that the summons was issued in the spring or early summer of 342; Athanasius met with Constans in Milan in the autumn of 342; Athanasius set out with Ossius from Trier in the summer of 343; and the council finally assembled a year and half after its convocation, in the autumn of 343.

In support of the 342 date, Richard and Elliott made much of the agenda of Athanasius as narrated in Apologia ad Constantium 4, saying that he was trying to give the impression that he was not involved in the preliminaries to the Council of Serdica, part of what led to enmity between Constans and Constantius.62 They argued that if the meeting of Athanasius and Constans was really a year or more before the council met, then Athanasius would not have needed to distance himself from its preparations. This argument fails to persuade, however, since negotiations for the Council of Serdica could have taken an extended period of time, as Elliott himself admitted, and thus Athanasius would have needed to clarify his involvement.63 Elliott advanced two other arguments against the interpretation of Apologia ad Constantium 4 by advocates of the 343 date. First, Elliott rejected the idea that Athanasius had a second meeting with Constans in Trier in 343. He points out, correctly in my opinion, that based on what Athanasius says in Apologia ad Constantium 4, the exiled bishop need not have met with Constans a second time. But at the same time nothing Athanasius says precludes it, and it remains a reasonable inference. If, however, the evidence of the second meeting were to be discounted, it only removes one piece of evidence for the 343 date, since the first meeting in Milan in the autumn of 342 still rules out the 342 date for the council. Second, Elliott suggested that Constans’ movements in 342 were not so extensive (from Milan to making peace with the Franks and back to Milan) as to preclude the council from taking place in the autumn of 342.64 That may well be true, but there is no independent evidence for Constans’ presence in Milan before his peace negotiations with the Franks. If Constans was in Milan only once in 342, in the autumn, then this rules out a possible meeting with Athanasius in Milan earlier in the year, and Elliott's objection crumbles. In the end, none of the arguments advanced by Richard or Elliott in support of their alternative interpretation of Apologia ad Constantium 4 is persuasive for a 342 date. Thus the arguments in favor of Apologia ad Constantium 4 supporting a 343 date for the council hold.


Schwartz's argument for a date of 342 rested heavily on two items, though the second far more than the first. The first is Festal Index 15, where it is recorded that “in this year” the Council of Serdica was held. One of the longstanding interpretative issues of the Festal Index, however, is precisely what its author, whom I call the “indexer,” meant by “in this year” and similar phrases. Each entry in the Index begins with several chronological indicators, the most important of which for purposes of dating are the date of Easter (according to both the Egyptian and Roman calendars), and then both the Roman consular year (which ran from 1 January to 31 December) and the indiction (which ran from September 1 to August 31) in which the Easter fell. In Festal Index 15, for example, Easter is assigned to 27 March in the consulship of Placidus and Romulus (1 January to 31 December 343) and in the first indiction (1 September 342 to 31 August 343). Accordingly, this Easter on 27 March occurred in 343. In many entries, as in Festal Index 15, in addition to the chronological data the indexer includes information about other events in the same “year.” But it is unclear how this “year” is calculated. The consular year and the indiction only overlap from 1 January to 31 August; should events from 1 September to 31 December be placed in the previous or the following year?65 

Festal Index 8 illustrates the dilemma: the date given for Easter is 18 April in the consulship of Nepotianus and Facundus (that is, 1 January to 31 December 336) and in the ninth indiction (1 September 335 to 31 August 336). So this entry records the date of Easter in 336. It also provides dates for four other events: the date Athanasius departed Alexandria for the Council of Tyre (11 July), the date he left Tyre for Constantinople (30 October), the date he met with Constantius (7 November), and the date he set out to Gaul for exile (5 February). Since the Council of Tyre assembled in the summer of 335, the first three events must have taken place in that year. Accordingly, only the final event occurs within the overlap of the consular year and the indiction (1 January to 31 August 336); the second and third events occur in the indiction before the start of the consular year (1 September to 31 December 335); and the first event occurred even before the start of the indiction. So when Festal Index 8 reports that “in this year” Athanasius went to the Council of Tyre, the “year” seems to correspond best but not exactly to the indiction since three of the four events happened during it and one of the four before it.

There has been much debate over which system the indexer used when he speaks of “this year.” Some hold that the Roman consular year is meant, others the Egyptian year (which ran from 29 August to 28 August and thus is quite close to the indiction). Many scholars, however, after comparing known dates of events mentioned in a given entry with the chronological data of the entry, suggest that the Festal Index is simply inconsistent: sometimes the Egyptian year seems to be used, other times the Roman consular year.66 Barnes has suggested that the indexer considered a “year” to span from Easter to Easter, and so the other events appended to an entry would have occurred in the year preceding the Easter listed in the entry.67 But even according to this system some events fall outside the Easter-to-Easter year in which they are placed.68 Thus it seems that no single system is exclusively used. Perhaps the old opinion that in each entry the indexer “takes a leading event or events, round which he groups antecedent or consequent facts, which often belong to other years” is the best way to approach the issue.69 And occasional errors cannot be ruled out.70 

Therefore, Festal Index 15 can be used to support a date for the Council of Serdica in the following ranges: 1 January to 31 December 343 (consular year); 1 September 342 to 31 August 343 (indiction or Egyptian year); or 12 April 342 to 27 March 343 (Easter-to-Easter year). Schwartz argued that Festal Index 15 used the Egyptian year, meaning that the council was held in the autumn of 342 (recall that he assumed that the delegates arrived in Antioch at Easter 343). In this he was followed by Richard (even though he placed the arrival of the delegates at Easter 344).71 Loofs, Seeck, Feder, Zeiller, and others maintained that the Index was based on the Roman consular year, and so proposed that the council was held in 343. Internal evidence cannot decide the issue; on its own Festal Index 15 is as ambiguous as it is inconclusive. A date in the autumn of 343 (and thus assuming the use of the consular year) coheres better with other evidence as interpreted above. If Richard is correct that the indiction is used, there is no reason to place the council in the autumn, since he dates the arrival of the delegation in Antioch to Easter 344.72 Accordingly, even if the indiction is used, it is possible for the council to have begun shortly before the indiction ended on 31 August 343 and to have continued for some months into the autumn of 343. In sum, while it is generally agreed now that the case for Festal Index 15 supporting a late 343 date for the Council of Serdica is stronger than the case for an autumn 342 date, this piece of evidence is too uncertain to be ultimately decisive.73 

Schwartz's case for a 342 date primarily appealed, however, to a historical note found in the Collectio Theodosii diaconi, the document that preserves the Historia acephala in the Codex Verona LX(58): …et congregata est synodus consolatu Constantini et Constantini aput Sardicam.74 The consular year indicated here would have to be either 320 or 329, both of which are too early for the Council of Serdica. In 1753 Pietro and Girolamo Ballerini emended the text to consolatu Constantii IV et Constantis III—that is, 346—in order to make it correspond more closely with the traditional date of 347.75 Taking his cue from them, perhaps, Schwartz likewise emended the text, attempting to harmonize this consular date with the evidence based on his interpretation of Festal Index 15: consolatu Constantii III et Constantis II—that is, 342.76 This emended text subsequently became the lynchpin for all arguments that dated the Council of Serdica to 342.77 Some accepted this emendation without question.78 Some scholars accepted it, but argued that the 342 date refers to the calling of the council, not its actual assembly.79 But this counterargument lacks merit; the text clearly says congregata est synodus, “the council assembled.”

While Schwartz's argument based upon the emendation reigned supreme for so long, especially among German scholars, nonetheless its force has more recently been considerably blunted by Richard Burgess’ ingenious counterargument. He rejected Schwartz's emendation and explained the unemended text as resulting from a miscalibration of indiction cycles when the original Greek was translated into Latin.80 As mentioned above, the unemended text could indicate the year 329, which, like the year 343, is able to correspond to the second indiction. In other words, even though the consular year 343 (consolatu Placidi et Romuli, from 1 January to 31 December 343) is normally associated with the first year of the indiction cycle (1 September 342 to 31 August 343),81 if the Council of Serdica were held in the autumn of 343, it would have fallen in the second year of the indiction cycle (1 September 343 to 31 August 344). Noting several contemporary examples of the ecclesiastical use of the indiction to date events like councils, Burgess suggested “that the original Greek of the Latin fragment dated the council [of Serdica] by an indiction and that when the work was translated into Latin sometime after c. 420, the obscure date (for Westerners) was converted into a more understandable consular date, albeit the wrong one.”82 As a result, the Latin translator was off by a complete indiction cycle, fifteen years (counting inclusively), because he converted the second year of the indiction that indicated 343 to the wrong consular year, one fifteen years earlier than he should have. The consular year he should have used was consolatu Placidi et Romuli. Accordingly, Burgess argued, the unemended text, “far from being an impediment to dating the council to 343 … in fact supports it.”83 It appears that this argument of Burgess was persuasive enough for Brennecke and his German colleagues to abandon Schwartz's 342 date for good.84 Yet, even if one does not accept Burgess’ account, to base the case for a date of 342 so fundamentally on a conjectural emendation from a document of doubtful reliability is quite inadvisable.85 


The only truly new argument for a 342 date in the wake of Schwartz was made by Marcel Richard in 1974. In addition to the remark that “in this year” the Council of Serdica was held, Festal Index 15 also reports that “there was an agreement made at Serdica respecting Easter, and a decree was issued to be binding for fifty years, which the Romans and Alexandrians everywhere announced in the usual manner.”86 The fact of this Easter accord finds confirmation in Athanasius's 18th festal letter from 346, in which he instructed the Alexandrians to celebrate Easter on 30 March, on the same day as the Romans, as had been “discussed in the holy synod” (at Serdica), instead of on 23 March, the date according to the “early custom” of the Alexandrians.87 Divergences in the celebration of Easter, for a number of different reasons, had long plagued Christianity. Constantine himself recognized the problem as early as 314 at the Council of Arles and put the issue on the agenda at the Council of Nicaea, where it was decided that a single system for computing the date of Easter should be in force throughout the empire.88 While the exact system endorsed by the Council is not preserved, it is presumed that the bishops of Rome and Alexandria were asked to collaborate in determining the date of Easter each year. Thus the “agreement made at Serdica respecting Easter” was not a new initiative, but another attempt to deal with a longstanding issue.

Richard argued that at some point between 341 and 343 the Romans changed their Easter computus, that is, their method of calculating Easter, replacing an eight-year cycle with an eighty-four-year cycle.89 The basis for his argument are the discrepancies between the dates on which Easter was celebrated according to the Chronography of 354 (whose ninth part records the Roman dates for Easter from 312 to 411) and the dates according to the eighty-four-year paschal cycle. Richard suggested that prior to 341 the discrepancies (which were in 313, 316, 317, 320, 323, 333, and 340) could be eliminated if one assumed an eight-year instead of an eighty-four-year cycle. Clear evidence for the new system is found only in 343, since in this year Romans celebrated Easter on 3 April, in accordance with the eighty-four-year cycle, whereas according to the eight-year cycle they would have celebrated Easter on 27 March. In the years 341 and 342 both cycles aligned. Accordingly, since at Easter 340 Rome was definitely still following the eight-year cycle and by Easter 343 definitely following the eighty-four-year cycle, Richard placed the change between 341 and 343.90 In lieu of other concrete evidence, Richard proposed that the change was made at the beginning of the 16th eight-year cycle, that is, starting with Easter 342, and that it was “not impossible that this change had been provoked by a historical event,” namely, the Council of Serdica, at which, as Index 15 records, an Easter accord was made between Rome and Alexandria.91 Since the new system was in place by Easter 343, Richard concluded that the council must have been held in 342, not 343. When Richard states that the Council “provoked” the change, he means that the Romans adopted a new method of calculating Easter in advance of the council: “It seems natural that before asking Athanasius to align the dates of Easter with those of Rome, the Latin bishops began by agreeing on a single computus.”92 

The chief evidence against this reconstruction, however, is the fact that Rome and Alexandria celebrated Easter on different days in 343: Rome on 3 April (in accordance with the eighty-four-year cycle) and Alexandria on 27 March. If the Romans’ change to their method of calculating Easter was made prior to a Council of Serdica held in late 342, and an accord on a common celebration of Easter was reached at the Council, then it is not clear why it was ignored the following year. Schwartz contended that Athanasius had not been able to inform the Alexandrians in time.93 Endorsing this contention, Richard advanced two possibilities: one, that Alexandria had not been informed of the accord in time, or two, that the Alexandrians believed that their calculation of Easter on 27 March was sufficient.94 

T. G. Elliott was the biggest advocate of Richard's proposal, claiming that no argument had been made specifically against it, only reassertions of older arguments for the 343 date of the Council of Serdica.95 Elliott endorsed Richard's argument that a new computus was adopted between 341 and 343, and that it was done in connection with Serdica. Elliott, however, differed from Richard in one respect: in his opinion, the Romans changed their method of calculating Easter after the council. He noted “the desirability of obtaining some agreement before making such a change,” meaning that he assumed that the Romans would not have changed their method until securing agreement with Alexandrians at the council.96 Furthermore, he added that if a 343 date for the council were maintained, it results in complications, “because the Romans must change their behavior, by Easter 343 at the latest, before they make the agreement, which seems too tactless a thing even for the Romans to do if they wanted an agreement at the approaching Council.”97 Accordingly, Elliott placed the Roman decision to adopt a new Easter computus after the Council of Serdica, in direct contradiction to Richard. As for explaining the discrepancy in 343, Elliott admits that Schwartz's argument was weak and simply suggested that the accord was not put into immediate effect.98 

For the sake of argument I will grant Richard's contention that the Romans changed their method of computing Easter as he described at some point after Easter 340 and before Easter 343.99 Richard characterized the connection between this change and the Council of Serdica as “not impossible”—the most he could claim based on the lack of evidence linking them. I suggest, however, that it is not necessary to associate them. I do not think that the decision had to be “provoked” by the Council of Serdica, since the issue of divergences in the celebration of Easter was longstanding. I agree with Richard that the decision was more likely made in advance of the council, but I maintain that, if a decision was made, it was not made because of the council. Any decision to change the Easter computus would have needed the support of bishops within Roman jurisdiction; accordingly, the Romans would have had to make the decision independently of its later becoming the basis for an Easter accord between Romans and Alexandrians at the Council of Serdica.100 Parvis has suggested that the decision was made at the Council of Rome in 341, “an internal Roman affair.”101 Athanasius had been in Rome since the summer of 339 and was present at the Roman council of 341; these factors could have been the impetus for the Romans to change their method of computing Easter. If Parvis is correct, the decision was made long before Constans and Constantius even decided to hold a council at Serdica. All this, of course, is moot if Richard is incorrect about the Romans changing their computus between 340 and 343. In that case, his whole argument for the Council of Serdica being held in 342 crumbles.102 

The use of the Easter accord to argue for a particular date for the Council of Serdica is persuasive only to the extent that the explanation of the discrepancy of 343 is persuasive. The discrepancy is better explained by the council's having been held in 343. Four arguments have been advanced by Schwartz, Richard, Brennecke, Elliott, and Ulrich to explain the divergence in the celebration of Easter in 343 immediately after the accord was reached at a Council of Serdica held in 342: first, that the interloper Gregory chose to ignore the accord;103 second, that Alexandria was not informed in time;104 third, that the Alexandrians thought their date of 27 March was in line with the accord; and fourth, that the accord was not put into immediate effect. The third explanation is implausible, as everyone was well-aware that the goal was a common celebration of Easter on the same day. The validity of the other three arguments depends on how one interprets the evidence for the Alexandrian celebration of Easter on 27 March (namely, Festal Index 15). Barnes claimed that the Index preserves the date on which Athanasius instructed the church of Alexandria to celebrate Easter, regardless of whether this instruction was obeyed.105 Elliott disagreed, claiming that the index preserves the date on which Easter was actually celebrated contrary to Athanasius' instruction (if indeed any instruction was given), the Athanasian indexer being unwilling to record an instance of Athanasius' failing to hold sway in his native church.106 Barnes seems to be correct. The commitment of Athanasius to writing festal letters during his exile has been noted by De Clerq, Barnard, and others, so there can be little doubt that each year Athanasius did instruct his church about the date of Easter. It appears that Athanasius wrote a short notification each Easter announcing the date of the next one, and then in late autumn composed a formal Festal Letter and sent it, so that it could be read in various places on Epiphany. In some years, however, the formal letter was not sent because of particular circumstances.107 The indexer constructed the index from the text of Athanasius' festal letters themselves, the short notifications, and other documents preserved in the archives of the episcopal chancery in Alexandria, and so must preserve the date on which Athanasius instructed the Alexandrian church to celebrate Easter.108,Index 15 records that Athanasius wrote a festal letter for Easter 343; however, it is not extant. Nonetheless, the indexer must have used it when compiling Index 15 and thus 27 March must be the date on which Athanasius instructed the Alexandrian church to celebrate Easter in 343. Accordingly, Barnes writes: “And if the index shows that Athanasius proposed to celebrate Easter in 343 at a date contrary to the decisions at Serdica, then either Athanasius disregarded the decisions of the council (which is impossible) or the council had not yet met.”109 So then, the first, second, and fourth arguments have no merit as an explanation for the divergence in the celebration of Easter in 343 if the Council of Serdica met in 342, since they would only be valid if the festal index preserved the actual date of the celebration of Easter, not the date proposed by Athanasius. Accordingly, the argument of Barnes is more persuasive: the Council of Serdica cannot have met in 342. The divergence in the celebration of Easter in 343 is better explained by the council's having not yet met.110 

Festal Index 15 makes no mention of the Romans' adopting a new Easter computus as the basis for the accord between the Romans and Alexandrians. It implies, however, that the Romans and Alexandrians agreed to follow the same computus for a period of fifty years. I suggest that the accord made at Serdica was not prompted by the decision of the Romans—if one was actually made111—but by the divergence in the celebration of Easter in 343. The collaboration on the date of Easter between Rome and Alexandria established at Nicaea had been largely successful in areas under their influence. In the twenty-five years after Nicaea they celebrated Easter on different days a week apart only three times: 326, 343, and 350.112 The experience of divergence in the celebration of Easter in 343—the first time since 326 the two areas had celebrated Easter apart from each other—is, I suggest, the motivation for the Easter accord at the Council of Serdica later that same year.

There is one further piece of evidence connected with Easter that supports a date of 343 for the Council of Serdica: a list of the Jewish dates for Passover from 328 to 343 which the eastern bishops brought to the council, also preserved in Codex Verona LX(58).113 Barnard has cited this list as additional evidence that the council was held in the autumn of 343.114 The purpose of the list seems to have been to demonstrate that up to the present time eastern Christians had not been celebrating Easter according the Jewish calculations of Passover, in violation of the Nicene decisions about Easter. It is thus a list of retrospective dates, not future ones.115 If the council had been held in the autumn of 342, the list would be expected to end with the date of Passover in 342.116 Accordingly, this list of Passover dates suggests that the council was held after Passover in 343. Thus, it constitutes an additional, albeit minor, piece of supporting evidence that the Council of Serdica was held in 343.


Those who have maintained that the Council of Serdica met in 342 ultimately based their case on interpretations of five key pieces of evidence, which, as I have shown, are more plausibly and more convincingly interpreted as indicating a date of 343. First, the Festal Index indicates that Athanasius celebrated three Easters after the council outside of Alexandria (344, 345, and 346) before returning home. Advocates of the 342 date suggested that the Festal Index is unreliable or inaccurate in this regard without offering any compelling reasons for this suspicion. Second, advocates of the 342 date did not offer any credible explanation or proof as to why there was such a delay between the end of the council and the western delegation's arrival in Antioch around Easter 344. All the reasons given were speculative. Third, advocates of the 342 date unquestioningly accepted Schwartz's conjectural emendation of the historical note found in Codex Verona 60(58), which is not only quite dubious methodologically but also, as Burgess has shown, unnecessary since the unemended text actually supports 343. Fourth, the explanations for the discrepancy in the Easter dates of 343 by advocates of the 342 date were based on an incorrect understanding of the source for the Easter dates in the Festal Index. Fifth, advocates of the 342 date held that in Apologia ad Constantium 4 Athanasius was counting time from his initial exchange of letters with the eastern emperor. I admit that they have legitimate textual reasons for this interpretation, even if I believe the passage is more plausibly interpreted as Athanasius' counting from the time of his exile from Alexandria. In the first four instances, however, either the evidence itself was suspect (the text Schwartz emended), or the interpretation was not supported by the evidence (doubting that Athanasius celebrated three Easters after the council before his return from exile), or based on a misunderstanding of the evidence (the Easter discrepancy of 343), or less compelling than the alternative interpretation (the time between the end of the council and the arrival of the delegation in Antioch). Accordingly, it can henceforth be accepted without demur that the Council of Serdica met in 343.

The evidence enumerated above furthermore suggests that the Council of Serdica opened some time in the second half of 343 and concluded at the latest between mid-October 343 and late-January 344. If the council began during the overlap of the consular year and the indiction in 343, then it might have started in mid to late August in 343 at the earliest, but the evidence of Festal Index 15 is too uncertain in this regard. Furthermore, we do not know how long the council met. Based on the known durations of the ecumenical councils we probably should not imagine the Council of Serdica, even though it is a well-known “fiasco” and its two factions never sat in council together, having met for more than two months.117 

Even still, can the range of possible dates be narrowed any further? In Historia Arianorum 16 Athanasius reports that the eastern bishops left the council early when they heard the news of Constantius's victory over the Persians. Barnes places the victory itself in summer or autumn of 343, and the arrival in Serdica of the imperial letter announcing the victory around November 343.118 Burgess suggests that the victory could have occurred as late as October 343 and that the triumph was held in Antioch on 31 January 344.119 Athanasius reports that the western bishops continued to meet as a council after the eastern bishops had successfully used the news of the victory as an excuse to depart. Before returning home, however, they stopped in Philippopolis, where they promulgated their documents. If these same eastern bishops participated in the triumph in Antioch in late January 344, they must have left Serdica at the latest between late November 343 and early January 344.

Accordingly, a good—but ultimately speculative—estimate for an exact timeframe of the Council of Serdica is that the bishops began arriving perhaps in late August and/or September, the western bishops in Serdica and the eastern bishops in Philippopolis,120 that the eastern bishops made the journey from Philippopolis to Serdica at some time in October,121 that the ultimately failed negotiations between the western and eastern bishops in Serdica lasted a week or more in October and perhaps into November 343,122 that the eastern bishops left Serdica by mid or late November 343 and stopped briefly in Philippopolis before heading home, and that the western bishops carried on with their conciliar business until some time between mid-December 343 and mid-January 344 at the latest, when emissaries were sent to Constans in Trier and then returned, and then the western delegates departed for the court of Constantius in Antioch. But the most that the evidence allows a chronographer to claim with any certitude is that the Council of Serdica, both its western and eastern complements, met in the autumn of 343. Over a century of debate on the issue has at long last brought us to this consensus. As this historiographical review and reassessment of all the evidence and all the arguments has shown, it is right that the debate over the date of the Council of Serdica now be closed.

R. P. C. Hanson, The Search for the Christian Doctrine of God: The Arian Controversy 318–381 AD (London: T&T Clark, 1988), 295; Susanna Elm, Sons of Hellenism, Fathers of the Church: Emperor Julian, Gregory of Nazianzus, and the Vision of Rome (Berkeley: University of California Press, 2012), 40; Carlos R. Galvão-Sobrinho, Doctrine and Power: Theological Controversy and Christian Leadership in the Later Roman Empire (Berkeley: University of California Press, 2013), 144; Glen L. Thompson, The Correspondence of Julius I (Washington, D.C.: The Catholic University of America Press, 2015), 119.
Lewis Ayres, Nicaea and its Legacy: An Approach to Fourth-Century Trinitarian Theology (Oxford: Oxford University Press, 2004), 123; John Behr, The Nicene Faith (Crestwood: St Vladimir's Seminary Press, 2004), 79.
Eamon Duffy, Saints & Sinners: A History of the Popes, 4th ed. (New Haven: Yale University Press, 1st ed. 1997; 4th ed. 2015), 31; Ivor J. Davidson, A Public Faith: From Constantine to the Medieval World, A.D. 312–600 (Grand Rapids: Baker Books, 2005), 52.
Succinct narratives of the Council of Serdica abound. The following set the council within the context of fourth-century ecclesio-political, imperial, and theological developments: Manlio Simonetti, Le crisi ariana nel IV secolo (Rome: Institutum patristicum Augustinianum, 1975), 167–187; Hanson, The Search for the Christian Doctrine of God, 293–306; T. D. Barnes, Athanasius and Constantius: Theology and Politics in the Constantinian Empire (Cambridge, Mass.: Harvard University Press, 1993), 71–81; and Ayres, Nicaea and its Legacy, 122–126.
Hanson, The Search for the Christian Doctrine of God, 295.
Hamilton Hess, The Early Development of Canon Law and the Council of Serdica (Oxford: Oxford University Press, 2002), 179. This is a second, augmented edition of his 1958 book on the same topic (see n. 23 below). On the Serdican canons, see also Christopher W. B Stephens, Canon Law and Episcopal Authority: The Canons of Antioch and Serdica (Oxford: Oxford University Press, 2015).
Edward Gibbon, The History of the Decline and Fall of the Roman Empire. Volume the First (1776) and Volume the Second (1781), Edited by David Womersly (London: Penguin Books, 1994), 802. Similarly, according to Gustave Bardy, in J. R. Palanque et al., The Church in the Christian Roman Empire. Volume I: The Church and the Arian Crisis (London: Burns, Oates & Washbourne, 1949), 156, “The Pass of Succa, between Serdica and Philippopolis, the boundary between Illyricum and Thrace, constituted from now on the boundary between the two communions, as it was between two empires.” Note, however, that Ayres (Nicaea and its Legacy, 123) contests the east-west dichotomy as overly simplistic.
The importance of chronography in understanding the relations between Constans and Constantius is exemplified by T. D. Barnes in Athanasius and Constantius.
On the rapprochement, see Hanson, The Search for the Christian Doctrine of God, 306–314; and Ayres, Nicaea and its Legacy, 126–130.
Collectanea Antiariana Parisina, Series A.IV.1,11 in S. Hilary episcopi Pictauiensis opera, iv, CSEL 65, ed. Alfred Feder (Vienna: Tempsky, 1916), 56, lines 19–20.
Chief studies of this topic include: Henry Chadwick, “The Fall of Eustathius of Antioch,” Journal of Theological Studies n.s. 49 (1948): 27–35; R. P. C. Hanson, “The Fate of Eustathius of Antioch,” Zeitschrift für Kirchengeschichte 95 (1984): 171–9; R. W. Burgess, “The Date of the Deposition of Eustathius of Antioch,” Journal of Theological Studies n.s. 51 (2000): 150–60; Sara Parvis, Marcellus of Ancyra and the Lost Years of the Arian Controversy (Oxford: Oxford University Press, 2007), 101–7; and Sophie Cartwright, The Theological Anthropology of Eustathius of Antioch (Oxford: Oxford University Press, 2015), 20–31.
Socrates, Historia ecclesiastica 2.20.4; Sozomen, Historia ecclesiastica 3.12.7. Both place the council in the consulship of Rufinus and Eusebius in the 11th year after Constantine's death—that is, 347. The evidence for the council provided by the fifth-century church historians Socrates, Sozomen, and Theodoret is surveyed by Leslie W. Barnard, The Council of Serdica 343 A.D. (Sofia: Synodal Publishing House, 1983), 119–127; also see appendices 6 and 7 in Barnes, Athanasius and Constantius, 205–211. For the Council of Serdica, all had access to at least some of the documents promulgated by it and the works of Athanasius. Socrates and Sozomen (and perhaps also Theodoret) also used the now-lost Synagoge of Sabinus of Heraclea, a collection of synodal documents with commentary. It is possible that the 347 date given by Socrates and Sozomen is derived from Sabinus, though Peter Van Nuffelen (Un héritage de paix et de piété: Étude sur les histories ecclésiastiques de Socrate et de Sozomene [Leuven: Peters, 2004], 358) says that Socrates places the council in this year “pour des raisons inconnues.” Sozomen and Theodoret also used Socrates, but neither repeats his account in every detail. Other sources were also probably available to each individually. Barnard considers Socrates’ account to be compromised by chronological errors and his ideological agenda, Sozomen's to be “of considerable historical worth” (125), and Theodoret's too brief to be useful. Barnes notes that Sozomen and Theodoret add details about the Council not found in Socrates. In particular, Theodoret's more extensive narrative of western delegation to Constantius after the Council “appears to reflect local knowledge or traditions” (210). With the exception of Socrates’ mention of the interval between the summoning and assembly of the council (see p. 296 below) and Theodoret's account of the western delegation to Constantius (see p. 292 below), the fifth-century church historians provide nothing of chronographical significance. There is further discussion of the church historians’ sources and ideological agendas, with references to relevant bibliography, in David Rohrbacher, The Historians of Late Antiquity (London: Routledge, 2002), 108–134; Hartmut Leppin, “Church Historians (I): Socrates, Sozomenus, and Theodoretus,” Greek and Roman Historiography in Late Antiquity: Fourth to Sixth century A.D., ed. Gabriele Marasco (Leiden: Brill, 2003), 219–254; and Van Nuffelen, Un héritage de paix et de piété.
See the discussion of Historia Arianorum 20–21 and Apologia ad Constantium 4 below.
This document is preserved in the famous Codex Verona LX(58) and was published for the first time by Scipione Maffei, who named it “Historia acephala ad Athanasium potissimum ac res Alexandrinas pertinens,” in Osservazioni letterarie, Tome III (Verona: J. Vallarsi, 1738), 60–83; reprinted in PG 26:1443–1450 as “Chronicon acephalum.” The best edition is now Annik Martin and Micheline Albert, Histoire “acéphale” et Index syriaque des Lettres festales d'Athanase d'Alexandrie, Sources Chrétiennes 317 (Paris: Cerf, 1985), 138–68.
J. D. Mansi, Sanctorum conciliorum et decretorum collectio nova, Supplementum (J. Salani and V. Junctinii, 1748), vol. 1, 175–176.
These documents were published for the first time by William Cureton, The Festal Letters of Athanasius (London: Society for the Publication of Oriental Texts, 1848). For the Festal Index, I use the edition of Martin and Albert, Histoire acéphale, 224–76. I also use the translation of the festal letters and index by Henry Burgess, The Festal Letters of S. Athanasius, Library of the Fathers (Oxford: Parker; London: Rivington, 1854), as revised by Jessie Payne Smith in Archibald Robertson, ed., St. Athanasius: Select Works and Letters, Select Library of the Nicene and Post-Nicene Fathers of the Christian church. Second series, 4 (Oxford: Parker; New York: Christian Literature Co., 1892), 503–53.
Eduard Schwartz, “Die Osterbriefe,” in Gesammelte Schriften III: Zur Geschichte des Athanasius (Berlin: De Gruyter, 1959), 1–29 at 11 (originally published in 1904); and “Von Konstantius Tod bis Sardika 342,” in Gesammelte Schriften III, 265–334 at 325–7 (originally published in 1911). For bibliography on the date of Serdica before 1900, see C.J. Hefele and H. Leclerq, Histoire des conciles d'après les documents originaux (Paris: Letouzey et Ané, 1907), tome 1, part 2, 737–742.
Friedrich Loofs, “Die chronologischen Angaben des sog. ‘Vorberichts’ zu den Festbriefen des Athanasius,” Sitzungsberichte der königlich preussischen Akademie der Wissenschaften 41 (1908): 1013–22; idem, “Zur Synode von Serdica,” Theologische Studien und Kritiken 82 (1909): 279–97 at 294–5; Otto Seeck, “Urkundenfälschungen des 4. Jahrhunderts,” Zeitschrift für Kirchengeschichte 30 (1909): 181–227 and 399–433 at 404–5; idem, Geschichte des Untergangs der antiken Welt. Anhang zum Vierten Band (Stuttgart: J. B. Metzler, 1911), 416–7. Also in favor of 343 was Erich Caspar, Geschichte des Papsttums von den Anfängen bis zur Höhe der Weltherrschaft (Tübingen: J. C. B. Mohr, 1930), vol. 1, 155–6 and 586–7.
Some examples (in addition to the studies cited below in n. 23): Gustave Bardy, “Sardique (Concile de),” in Dictionnaire de théologie Catholique 14, eds. A. Vacant, E. Mangenot, and É. Amann (Paris: Letouzey, 1939), 1109–14; Simonetti, Le crisi ariana, 167 n. 12; idem, “Serdica (Sardica). II. Councils,” in Encyclopedia of Ancient Christianity, ed. Angelo Di Berardino (Downers Grove: IVP Academic, 2014), vol. 3, 543–4; Martin and Albert, Histoire acéphale, 289 n. 42; Hanson, The Search for the Christian Doctrine of God, 293–4 n. 64; Annick Martin, Athanase d'Alexandrie et l’église d’Égypte au IVe siècle (328–373) (Rome: École Française de Rome, 1996), 422–3; Alberto Camplani, Atanasio di Alessandria: Lettere festali. Anonimo: Indice delle lettere festali (Milano: Paoline, 2003), 88, 97, 105–6, 114, etc.; Ayres, Nicaea and its Legacy, 122; David M. Gywnn, ‘The Eusebians’: The Polemic of Athanasius of Alexandria and the Construction of the ‘Arian’ Controversy (Oxford: Oxford University Press, 2007), 95; and Alden A. Mosshammer, The Easter Computus and the Origins of the Christian Era (Oxford: Oxford University Press, 2008), 182–3.
Some examples (in addition to the studies cited below in n. 22): Hans Lietzmann, A History of the Early Church. III: From Constantine to Julian (Cleveland and New York: Meridian Books, 1961), 199–200; Hans-Georg Opitz, Athanasius Werke II/1: Die Apologien (Berlin: De Gruyter, 1935–41), 114 n. 2 (this is a note on Apologia secunda [=Apologia contra Arianos] 36.1 that endorses Schwartz); Wilhelm Schneemelcher, “Serdika 342: Ein Beitrag zum Problem Ost und West in der Alten Kirche,” in Evangelische Theologie, Sonderheft: Ecclesia semper reformanda, eds. W. Schneemelcher and K. G. Steck (Munich: Chr. Kaiser Verlag, 1952), 83–104; idem, “Die Kirchwiehsynode von Antiochien 341,” in Bonner Festgabe: Johannes Straub zum 65. Geburstag am 18. Oktober 1977, eds. Adolf Lippold and Nikolaus Himmelmann (Bonn: Rheinland-Verlag; In Kommission R. Habelt, 1977), 319–346 at 330 n. 42; Klaus Seibt, Die Theologie des Markell von Ankyra (Berlin: De Gruyter, 1994), 13; and Markus Vinzent, Markell von Ankyra: Die Fragmente und Der Brief an Julius von Rom (Leiden: Brill, 1997), xxii.
Hanns Christof Brennecke, Uta Heil, Annette von Stockhausen, and Angelika Wintjes, eds., Athanasius Werke. Dritter Band. Erster Teil: Dokumente zur Geschichte des arianischen Streites. 3. Lieferung: Bis zur Ekthesis Makrostichos (Berlin/New York: De Gruyter, 2007), 179. They state that the council most likely (“aller Wahrscheinlichkeit nach”) took place in the autumn of 343, and remark that while individual pieces of evidence are not without controversy, in the aggregate (“in ihrer Gesamtheit”) they support this date.
William Telfer, “Paul of Constantinople,” Harvard Theological Review 43 (1950): 31–92; Marcel Richard, “Le comput pascal par octaétéris,” Le Muséon 87 (1974): 307–39; Hanns Christoff Brennecke, Hilarius von Poitiers und die Bischofsopposition gegen Konstantius II (Berlin: De Gruyter, 1984), 25–9; T. G. Elliott, “The Date of the Council of Serdica,” The Ancient History Bulletin 2.3 (1988): 65–72; and Jörg Ulrich, Die Anfänge der abendländischen Rezeption des Nizänums (Berlin: De Gruyter, 1994), 39–44.
Alfred Feder, Studien zu Hilarius von Poitiers I, Sitzungsberichte / Kaiserliche Akademie der Wissenschaften in Wien, Philosophisch-Historische Klasse 162.4 (Vienna: A. Hölder, 1910), 87–88; Jacques Zeiller, Les origines chrétiennes dans les provinces danubiennes de l'empire romain (Paris: E. de Boccard, 1918), 228–31; Victor C. De Clerq, Ossius of Cordova (Washington D.C.: Catholic University of America Press, 1954), 313–24; Hamilton Hess, The Canons of the Council of Sardica A.D. 343: A Landmark in the Early Development of Canon Law (Oxford: Clarendon Press, 1958), 140–4; Charles Pietri, Roma Christiana: Recherches sur l'Eglise de Rome, sa politique, son idéologie de Militade à Sixte III (311–440) (Rome: Écoles françaises de Rome, 1976), vol. 1, 212–3 n. 3; T. D. Barnes, “Emperor and Bishops, AD 324–344: Some Problems,” American Journal of Ancient History 3 (1978): 53–75 at 67–9; Leslie W. Barnard, “The Council of Serdica: Some Problems Re-assessed,” Annuarium Historiae Conciliorum 12 (1980): 1–25; idem, “The Council of Serdica: Two Questions Reconsidered,” in Ancient Bulgaria, ed. A.G. Poulter (Nottingham: University of Nottingham, 1983), Part 2, 215–31; idem, The Council of Serdica 343 A.D. (Sofia: Synodal Publishing House, 1983), 49–55; Barnes, Athanasius and Constantius, 259 n. 2; Richard W. Burgess, Studies in Eusebian and Post-Eusebian Chronography (Stuttgart: Franz Steiner Verlag, 1999), 241–44; and Parvis, Marcellus of Ancyra, 210–24.
See notes 19 and 20 above. Telfer advanced a novel thesis that the Council of Serdica must have met in 342 based on what can be recovered from certain texts touching on Paul of Constantinople. While endorsed by Brennecke, Hilarius, 27, Telfer's proposal has been adequately summarized and rejected by De Clerq, Ossius of Cordova, 322–4; Hess, The Canons, 144; Pietri, Roma Christiana, 212–3 n. 3; Barnard, “Some Problems,” 4–6; Barnard, “Two Questions,” 223–6; Barnard, The Council of Serdica, 52–4; and Elliott, “The Date,” 71. Accordingly, I will not discuss Telfer's thesis any further.
Barnes, “Emperor and Bishops,” 67.
Festal Index 11. See Barnes, Athanasius and Constantius, 46 and 50.
Festal Index 11 and Historia acephala 1,1.
Festal Index 16–18. See also Athanasius, Apologia ad Constantium 4.5.
Feder, Studien, 87; Zeiller, Les origines chrétiennes, 230; De Clerq, Ossius of Cordova, 314; Hess, The Canons, 143; Pietri, Roma Christiana, 212–3 n. 3; Barnes, “Emperor and Bishops,” 67; Barnard, “Some Problems,” 4; idem, “Two Questions,” 223; idem, The Council of Serdica, 52; Burgess, Studies, 241–2 n. 168; Parvis, Marcellus of Ancyra, 213. Schwartz, Gesammelte Schriften III, 331, argued that the Festal Index was corrupt or unreliable, pointing to a few examples of this elsewhere in the document, and that Athanasius must have spent two Easters at either Naissus or Aquileia. In the same vein, Richard (“Le comput pascal,” 322–327) argued that Athanasius spent the Easters of 343 and 344 at Naissus. Elliott (“The Date,” 70–71) gave tepid support to Richard's view. Brennecke (Hilarius, 28) and Ulrich (Die Anfänge, 41–42) simply appealed to the arguments of Richard and Schwartz. Any interpretation based upon a purported corruption, unreliability, or inaccuracy of a text when there are no compelling reasons for such a suspicion (except errors elsewhere or that it doesn't support your thesis) is highly suspect.
Theodoret, Historia ecclesiastica 2.8.54; Klaus M. Girardet, Kaisergericht und Bischofsgericht. Studien zu den Anfängen des Donatistenstreites (313−315) und zum Prozess des Athanasius von Alexandrien (328−346) (Bonn: R. Habelt, 1975), 143 n. 162; Brennecke, Hilarius, 48; Barnes, Athanasius and Constantius, 87.
Athanasius, Historia Arianorum 21.1 (Opitz, Athanasius Werke II/1, 194, line 1).
Athanasius, Historia Arianorum 21.2 (Opitz, Athanasius Werke II/1, 194, line 5).
Festal Index 18 provides the day, while Historia Arianorum 21.2, Apologia contra Arianos 51, and Historia acephala 1,1 indicate the year. See Barnes, “Emperor and Bishops,” 75 n. 97.
Throughout this study I assume that bishops were able to travel on the cursus publicus. For its use by the bishops travelling to and from Serdica, see Barnard, The Council of Serdica, 43, 45, and 64. Distances and possible routes have been calculated with “ORBIS: The Stanford Geospatial Network Model of the Roman World” ( The parameters used in these calculations are: the appropriate season; the “fastest” route; and travel by road, river, coastal sea, and open sea. For road travel, the “fast carriage” rate of 67 kilometers per day (=42 miles per day) has been used as the most appropriate for journeys on the cursus publicus. When I say travel “by sea” I mean a route that is combination of travel by road, coastal sea, and open sea (where possible). Note that ORBIS has been used to estimate the shortest possible length of a journey between two cities; no claim is being made that any given journey took exactly what ORBIS estimates. In my chronological estimates I always use a range of possibilities, from the shortest possible to double that time. At minimum, the journey from Serdica to Antioch would have taken a little more than two weeks by sea (2043 km/1270 mi; 15.5 days) or approximately a month by road (1672 km/1040 mi; 24.9 days); see Map 1. For our purposes, then, the time to travel from Serdica to Antioch would be anywhere between a little more than two weeks and approximately two months.
Feder, Studien, 87; De Clerq, Ossius of Cordova, 317–8; Hess, The Canons, 143–4; Pietri, Roma Christiana, 212–3 n. 3; Barnes, “Emperor and Bishops,” 67–8; Barnard, “Some Problems,” 6–7; Barnard, “Two Questions,” 226–7, Barnard, The Council of Serdica, 54; Parvis, Marcellus of Ancyra, 216–7.
Eduard Schwartz, Gesammelte Schriften IV: Zur Geschichte der alten Kirche und ihres Rechts (Berlin: De Gruyter, 1960), 13–14; Opitz, Athanasius Werke II/1, 193 (a note on Historia Arianorum 20.2); Lietzmann, A History of the Early Church, 207.
Richard, “Le comput pascal,” 320–2; Brennecke, Hilarius, 47–8; and Ulrich, Die Anfänge, 42–3; Girardet (Kaisergericht und Bischofsgericht, 146–7) does the same.
Theodoret, Historia ecclesiastica 2.8.54. Earlier Telfer (“Paul of Constantinople,” 91–92) had rejected the Athanasian evidence, as it conflicted with his date of 342 for the Council of Serdica; for a response, see Hess, The Canons, 143–4; Barnard, “Some Problems,” 7; Barnard, “Two Questions,” 227; and Barnard, The Council of Serdica, 54–55.
Richard, “Le comput pascal,” 322. Ulrich (Die Anfänge, 43) repeats this explanation. Citing Girardet (Kaisergericht und Bischofsgericht, 143), Ulrich also suggests that Constantius closed the borders to westerners.
Elliott (“The Date,” 69) supported Richard's rejection of the Athanasian evidence, proposing that the bishops of Serdica would not have inserted themselves in the negotiations between the two emperors. But as he himself admits, the evidence of Athanasius and Theodoret is reconcilable, as the council and the emperor surely collaborated on the decision to send delegates and its implementation.
Parvis, Marcellus of Ancyra, 217.
Ulrich, Die Anfänge, 44. This is reminiscent of Schwartz's suggestion that the journey took 18 months because the delegates travelled “langsam und mit Aufenthalten” (Gesammelte Schriften IV, 14 n. 1).
Parvis, Marcellus of Ancyra, 217.
A point made by Girardet, Kaisergericht und Bischofsgericht, 146.
For a list of the bishops at the Council of Serdica, see Parvis, Marcellus of Ancyra, 263–4. Even though Theodoret, Historia ecclesiastica 2.8.54, refers to both bishops as attendees of the council, as Parvis notes, this “could be a mere inference” (Marcellus of Ancyra, 224 n. 202).
Parvis, Marcellus of Ancyra, 224 n. 202.
Barnes, Athanasius and Constantius, 225.
The difference between travel by sea and by road is negligible. At minimum, either mode of transport would have taken a little less than a month: 26.9 days by sea (2270 km/1411 mi) or 28.5 days by road (1906 km/1184 mi); see Map 2.
At the end of 342 Constans was in Milan. The distance from Serdica to Milan was by road 1397 km (868 mi) and would have taken 20.9 days; by sea it was 1718 km (1068 mi) and would have taken 19.3 days. At minimum, then, a round-trip would have taken about 40 days by either mode of transport.
At this point it is worth mentioning that the arrival of the delegates in Antioch at Easter has led to the widespread assumption that the council itself was held in the autumn. However, this is likely only if the 343 date is accepted. Advocates of the 342 date, who maintain a longer interval of time between the conclusion of the council and the arrival of the delegates, have no reason to assume an autumn timeframe for a council in 342, though they often do.
Apologia ad Constantium 4.3 (Hans Christof Brennecke, Uta Heil, and Anette von Stockhausen, eds., Athanasius II/1: Die Apologien. 8. Lieferung [Berlin: De Gruyter, 2006], 282, line 17): τριῶν τοίνυν ἐτῶν παρελθόντων <τῷ τετάρ>τῳ ἐνιαυτῷ γράφει κελεύσας ἀπαντῆσαί με πρὸς αὐτόν.
Counting from the Athanasius's initial exchange of letters with Constans is endorsed by Schwartz, Gesammelte Schriften III, 326; Girardet, Kaisergericht und Bischofsgericht, 108; Brennecke, Hilarius, 19–20 and 27–28; and Ulrich, Die Anfänge, 40–1.
Parvis (Marcellus of Ancyra, 216) enumerates the options. On Constans’ presence in Milan in 341, see Barnes, Athanasius and Constantius, 225.
See Apologia ad Constantium 4.1. In this section Athanasius begins the narrative of his travels, starting with his departure from Alexandria in 339, then in 4.2 refers back to his initial exchange of letters with Constans in early 338. This interpretation is supported by Brennecke, Heil, and von Stockhausen (Athanasius II/1: Die Apologien, 282), in a note on Apologia ad Constantium 4.3. Feder (Studien, 87), Hess (The Canons, 142), and other scholars who support a 343 date for the Council of Serdica hold that Athanasius is counting from the beginning of his second exile.
Feder, Studien, 87; De Clerq, Ossius of Cordova, 315–7; Hess, The Canons, 142–3; Pietri, Roma Christiana, 212–3 n. 3; Barnes, “Emperor and Bishops,” 67–8; Barnard, “Some Problems,” 2–3; Barnard, “Two Questions,” 221–222; Barnard, The Council of Serdica, 50–1.
This is precisely when Otto Seeck dates it (between 1 November and 4 December); see Regesten der Kaiser und Päpste für die Jahre 311 bis 476 n. Chr. Vorarbeit zu einer Prosopographie der christlichen Kaiserzeit (Stuttgart: J. B. Metzler, 1919), 191. He is followed by Caspar, Geschichte des Papsttums, vol. 1, 587. Brennecke, Heil, and von Stockhausen (Athanasius II/1: Die Apologien, 282), in a note on Apologia ad Constantium 4.3, place the meeting in November and December 342.
Barnes, “Emperor and Bishops,” 68; idem, Athanasius and Constantius, 69–70 and 225.
Elliott (“The Date,” 68) denies this second meeting; see below.
De Clerq, Ossius of Cordova, 317. Also see n. 60 below.
It has been claimed that the eastern bishops travelled slowly to Serdica, making it impossible, if the summons had been issued in mid-342, that they would have been able to reach Serdica in time for a council in the autumn of 342; see De Clerq, Ossius, 336–7, and Barnard, “Some Problems,” 2–3, idem, “Two Questions,” 221, idem, The Council of Serdica, 50, who cite various statements in the eastern encyclical (Collectanea Antiariana Parisina, Series A.IV.1,16 and 25 [Alfred Feder, S. Hilary Episcopi Pictauiensis Opera, iv, CSEL 65 (Vienna: Tempsky, 1916), 58 and 64]); Hess, The Canons, 143, who cites the western encyclical: Venientes etenim Serdicam per singula loca synodos faciebant inter se, “As they travelled to Serdica they were holding assemblies among themselves at various places” (Collectanea Antiariana Parisina, Series B.II.1, 7 [CSEL 65, 120]). On the one hand, the evidence cited by De Clerq and Barnard seems to me rhetorical bluster, as admitted by Barnard, who nonetheless refused to dismiss it, stating, “While some of these complaints should be taken cum grano salis there is little doubt that the Easterners dragged their heels on the way to Serdica.” On the other hand, the evidence cited by Hess seems to me to refer to the eastern bishops’ meetings in Philippopolis before arriving in Serdica. As noted by Ulrich (Die Anfänge, 43), in the same eastern encyclical the bishops claimed to have hastened to Serdica: occurimus ad Serdicam litteris imperator conventi (Hilary, Collectanea Antiariana Parisina, series A.IV.1,16 [CSEL 65, 58]). Furthermore, Athanasius describes the eastern bishops as having travelled to Serdica “with eagerness” (προθύμως) and “with zeal” (μετὰ σπουδῆς); see Historia Arianorum 15.3 and 15.4 (H.G. Opitz, Athanasius Werke II/1 [Berlin: De Gruyter, 1940], 190,16–17 and 26). Accordingly, there is both not sufficient evidence and sufficient counter-evidence to reject any argument for the impossibility of the Council of Serdica meeting in the autumn of 342 based on the purported slowness of the eastern bishops travelling to Serdica.
Socrates, Historia ecclesiastica 2.20.6 (G. C. Hansen, Sokrates Kirchengeschichte, Die Griechischen Christlichen Schriftsteller n.f. 1 [Berlin: Akademie Verlag, 1995], 118): ἐνιαυτοῦ καὶ ἓξ μηνῶν διαγενομένων, ἀφ’ οὗ ἥ τε σύνοδος ἐκεκήρυκτο. Socrates is disputing the complaint of some eastern bishops that there was not enough time between the summons and the assembly of the council.
Richard, “Le comput pascal,” 326–7; Elliot, “The Date,” 67–9. On the historical context of Apologia ad Constantium, see Barnes, Athanasius and Constantius, 196–7.
Elliott, “The Date of the Council of Serdica,” 68. Barnes (Athanasius and Constantius, 69) described Constantius as having “acceded reluctantly” to Constans’ demand for a council, and Parvis (Marcellus of Ancyra, 216) as having “long continued to drag his heels over the proposed ecumenical synod,” both suggesting a lengthy prelude to the summoning of the council.
Barnes (Athanasius and Constantius, 225) also places Constans in Trier in the summer of 342, a fact that Elliott omits.
This is the precise problem, as stated by Martin and Albert, Histoire acéphale, 73–8. In what follows I am indebted to Martin's analysis.
Martin and Albert (Histoire acéphale, 73–8) explains the indexer's tendency to list events that actually belong to two different years, whether Egyptian or consular, in a single year, as due to the combined use of Egyptian months and consular years. On the inconsistency of the index, see also Barnard, “Two Questions,” 220–1; Ulrich, Die Anfänge, 40; Parvis, Marcellus of Ancyra, 212–3.
Barnes, Athanasius and Constantius, 5 and 237–8.
For example, the Easter-to-Easter year for Festal Index 18 would be 8 April 345 to 30 March 346, but this entry includes Athanasius's return to Alexandria from his second exile on 21 October 346. Another example: the Easter-to-Easter year for Festal Index 33 would be 24 April 360 to 8 April 361, but this entry includes Constantius' death on 3 November 361. The inclusion of this event in Festal Index 33 only makes sense if the indexer was using the consular year, since the fourth indiction ended on 31 August 361.
Robertson (Athanasius, 501), expressing a common view. According to my calculations, there are approximately 32 datable events appended to 19 entries. In 15 of these, the consular year includes all the events in the entry; in 9, the indiction; and in 5, the Easter-to-Easter year.
See Camplani, Atanasio di Alessandria: Lettere festali, 108–11.
Richard, “Le comput pascal,” 319.
Richard (“Le comput pascal,” 319) seems to assume an autumn timeframe for the council because that is the only period at which the indiction of Festal Index 15 and his preferred year of 342 overlap.
That the uncertainty of Festal Index 15 in this regard ultimately voids its usefulness in any argument for the date of the council, especially in face of the Schwartz's second piece of evidence (to be discussed presently), has been noted by Brennecke (Hilarius, 26–8) and others.
C. H. Turner, ed., Ecclesiae Occidentalis Monumenta Iuris Antiquissima, Tomi prioris fasciculus alter [=EOMIA 1.2] (Oxford: Clarendon Press, 1913–1939), 637. Turner prints the emendation of Schwartz (to be discussed presently), but notes the manuscript reading in the apparatus.
PL 56:146.
Schwartz, Gesammelte Schriften III, 326.
As noted by Hess, The Canons, 140; Richard, “Le comput pascal,” 326; Brennecke, Hilarius, 28; Elliott, “The Date of the Council of Serdica,” 65; Burgess, Studies, 242.
E.g. Richard, “Le comput pascal,” 319; Pietri, Roma christiana, 212–3 n. 3; Brennecke, Hilarius, 27; and Ulrich, Die Anfänge, 40.
Loofs, “Zur Synode von Serdica,” 294–5; Feder, Studien, 87–8; Zeiller, Les origines chrétiennes, 230; De Clerq, Ossius of Cordova, 320–1; Simonetti, Crisi, 167 n. 12; Barnes, Athanasius and Constantius, 259 n. 2.
Burgess, Studies, 241–3.
For example, as in Festal Index 15, as well as in the Fasti Heracliani, edited by H. Usener in Theodor Mommsen, ed., Chronica minora saec. IV.V.VI.VII, Volume III, Monumenta Germaniae historica: Auctorum antiquissimorum 13 (Berlin: Weidmannos, 1898), 399.
Burgess, Studies, 243.
Burgess, Studies, 243.
Brennecke, Heil, von Stockhausen, and Wintjes, Athanasius Werke. Dritter Band. Erster Teil, 179. They point out that Burgess makes this argument with great likelihood (“…kann Burgess sehr wahrscheinlich machen…”).
On the unreliable chronology of the Codex Verona, see Martin and Albert, Histoire acéphale, 35–49; and Parvis, Marcellus of Ancyra, 212.
Translation by Burgess, The Festal Letters, xix, as revised by Smith in Robertson, St. Athanasius, 504.
Translation by Burgess, The Festal Letters, 119–20, as revised by Smith in Robertson, St. Athanasius, 544.
See Mark DelCogliano, “The Promotion of the Constantinian Agenda in Eusebius of Caesarea's On the Feast of Pascha,” in Reconsidering Eusebius: Collected Papers on Literary, Historical, and Theological Issues, Vigiliae Christianae Supplements 107, eds. Sabrina Inowlocki and Claudio Zamagni (Leiden: Brill, 2011), 39–68 at 40–46. The main issue at Nicaea was to eliminate the so-called Protopaschite method of computing the date of Easter, which resulted in the celebration of Easter a month apart.
Richard, “Le comput pascal,” 316–319.
Richard should have more accurately said that the change was made between post-Easter 340 and pre-Easter 343.
Richard, “Le comput pascal,” 319.
Richard, “Le comput pascal,” 327.
Schwartz, Christliche und jüdische Ostertafeln (Berlin: Weidmann, 1905), 51.
Richard, “Le comput pascal,” 327.
Elliott, “The Date,” 65.
Elliott, “The Date,” 66.
Elliott, “The Date,” 67.
Elliott, “The Date,” 66 and 69–70.
But also see n. 102 below.
On the independence of the Roman decision to change their computus and the Council of Serdica, see also Camplani, Atanasio di Alessandria: Lettere festali, 114.
Parvis, Marcellus of Ancyra, 215.
Mosshammer (The Easter Computus, 128–9) does not endorse Richard's proposal.
This is the only explanation of the discrepancy advanced by Brennecke, Hilarius, 28 n. 51; and Ulrich, Die Anfänge, 41.
This is the explanation of Schwartz, Christliche und jüdische Ostertafeln, 51.
Barnes, “Emperor and Bishops,” 68.
Elliott, “The Date of the Council of Serdica,” 69–70.
For example, Festal Letter 17 is a short notification that was written at Easter 344 to announce the date of Easter 345. The Index reports that no formal Festal Letter was written (in late 344) for 345.
See Alberto Camplani, Le lettere festali di Atanasio di Alessandria: Studio storico-critico (Roma: C.I.M., 1989), 106–112. On the origins of the Index in the archives of the episcopal chancery, see Martin and Albert, Histoire acéphale, 69–73, and Camplani, Le lettere festali di Atanasio di Alessandria, 87–111.
Barnes, “Emperor and Bishops,” 68.
Zeiller, Les origines chrétiennes, 229–30; Feder, Studien, 88; De Clerq, Ossius of Cordova, 318–319; Barnard, “Some Problems,” 3–4; idem, “Two Questions,” 222–3; idem, The Council of Serdica, 51.
See n. 102 above.
There is evidence that areas outside the influence of Rome or Alexandria continued to celebrate Easter according to the Protopaschite method even after the Nicene agreement; see DelCogliano, “The Promotion,” 45–6.
EOMIA 1.2, 641–643.
Barnard, “Some Problems,” 4; idem, “Two Questions,” 223.
See Parvis, Marcellus of Ancyra, 215–6, citing the work of Sacha Stern.
Elliott (“The Date,” 70) criticizes Barnard for overlooking Schwartz's discussion of this list in connection with the Council of Serdica and repeats Schwartz's argument that only the date of Passover for 343 in the list was prospective. Ulrich (Die Anfänge, 41) makes the same argument, but viewing all the dates as retrospective makes more sense. Even so, this is not a clinching piece of evidence but merely supportive.
The Council of Nicaea met from 20 May to 19 June 325 (4 weeks); that of Constantinople from some time in May to 9 July 381 (about six or seven weeks); that of Ephesus I from 22 June to 31 July (5 weeks); and that of Chalcedon from 8 October to 1 November 451 (3 weeks). Richard (“Le comput pascal,” 320–1) suggested a duration between fifteen days and a month.
Barnes, “Emperor and Bishops,” 69; idem, Athanasius and Constantius, 220. Elliott (“The Date of the Council of Serdica,” 69) considers the evidence of Historia Arianorum 16.2 as one of the major chronological arguments of Barnes, but Barnes himself does not use it thus.
Burgess, Studies, 241 and 243–4.
Barnard (“Some Problems,” 18; The Council of Serdica, 65) proposed placing the arrival of the eastern bishops in Philippopolis in late August. Barnes (Athanasius and Constantius, 259 n. 2) countered that “there seems to be no ancient evidence that the council met in the sweltering heat of late summer.”
At 141 km (88 mi) from Serdica, Philippopolis was a two- to four-day journey, though possibly longer because of the need to travel through the Succi or Souki (Ihtiman) pass.
Barnard (The Council of Serdica, 70) proposes that the eastern bishops spent “at least a week, probably more” in Serdica.