In the sixteenth century, chronic wars and a high concentration of towns made the Low Countries one of Europe's prime laboratories for innovations in military architecture and urbanism. The 1553 inspection tour of the region by engineers Giovanni Maria Olgiati and Sebastian van Noyen marked the assimilation of “Italian-style” fortifications into Netherlandish practice and the transition there from defenses with bastions to proper bastioned systems. Olgiati and Van Noyen's joint tour is well documented through a dozen design drawings now held at the Vatican Library, Turin's Archivio di Stato, and Madrid's Palacio Real, as well as a closely related atlas in Turin and complementary archival records. As Pieter Martens discusses in Planning Bastions: Olgiati and Van Noyen in the Low Countries in 1553, these materials, including many hitherto unknown plans, provide new insights into the design process, offer a unique panorama of the Low Countries' border defenses at this critical moment, and illuminate the genesis and spread of bastioned fortifications in Europe.
Although not well known today, Giovanni Maria Olgiati (ca. 1494−1557) was one of the most important military architects of the sixteenth century.1 From about 1535 until his death in 1557, he worked on the fortifications of at least seventy towns and fortresses, mainly in Northern Italy. From 1541 he was the chief engineer of the Duchy of Milan, but he was also active in Piedmont, Liguria, Corsica, and Tuscany. Among his most prominent achievements are the fortifications of Genoa, at which he worked from 1536, and the new bastioned city walls of Milan, which he designed in 1549.2 By the middle of the century he enjoyed recognition as one of Europe's preeminent engineers. In 1553, by order of Emperor Charles V, and much against his will, Olgiati was summoned from Italy to the Low Countries to work on fortifications there.3 His mission consisted of inspecting and improving the main strongholds along the border with France and was coordinated by the central government in Brussels under the command of the governor of the Low Countries, the emperor's sister, Mary of Hungary.
Olgiati's stay in the Low Countries was brief—he returned to Italy after six months—but it has great significance for the history of military architecture and town planning. To start with, a dozen drawings from Olgiati's tour of inspection have been preserved. They are among the earliest documents of their kind to have survived. With the exception of three drawings by Alessandro Pasqualini from the 1540s, they are the oldest fortification drawings known to have been made by an Italian engineer in the Low Countries, predating the well-known series of manuscript town plans created by Jacob van Deventer in the years 1558–72. For several towns the earliest known plans are those made by Olgiati. Moreover, Olgiati's drawings show both the existing situations and his proposed modifications, so the evidence they offer is threefold: an exceptional record of the state of the Low Countries' fortifications around the middle of the sixteenth century, a unique testimony of the engineer's design method, and a demonstration of the rapid evolution of military architecture in this period. Indeed, many of the fortifications Olgiati proposed to alter were new; designed by others a few years earlier, they were often not yet finished. Still, Olgiati introduced fundamental improvements that constituted the concluding stage of the development of the bastioned system.4
New drawings and other sources pertaining to Olgiati and his work have recently come to light. These complete the hitherto fragmentary picture of his activities in the Low Countries and greatly clarify his working method and legacy. This article offers a fresh analysis based on varied and widely dispersed documents.5 Besides building accounts and correspondence, these include a dozen drawings in three different collections: Olgiati's long-known plans in the Vatican Library and in Turin's Archivio di Stato are now complemented by an important but unstudied set of plans held in Madrid's Palacio Real.6 Close scrutiny of these drawings allows a new interpretation of another group of plans preserved in an atlas in the Biblioteca Nazionale in Turin (hereafter referred to as the BNT atlas). This atlas contains more than twenty unidentified and undated plans of fortifications in the Low Countries, most of which were unknown until now. They are closely related to Olgiati's tour of inspection and crucial to understanding his working method. They also enable us to sketch a broader picture of the fortifications along the southern border of the Low Countries in the early 1550s—an area that, because of its high density of towns and chronic wars with France, was one of Europe's prime laboratories for innovations in military architecture and town planning.
Bulwarks, Bastions, Bastioned Systems
Capable of resisting artillery and applied for three centuries to countless towns and forts throughout the world, the bastion was, in the words of English historian Sir John Hale, “the most significant of all architectural forms evolved during the Renaissance.”7 The conventional view is that the bastion originated in Italy in the period 1450–1535 and then spread across Europe as Italian engineers were employed by foreign rulers. Yet recent research has revealed independent experiments with similar defensive structures in other parts of Europe and made clear that the long and gradual evolution of the bastioned system was not an exclusively Italian affair.8 This article focuses on a key stage of this development outside Italy.
Before the universal adoption of the bastion, the enceintes (defensive perimeters) of towns and fortresses were equipped with other types of defensive works—such as artillery towers at the corners and bulwarks (or boulevards) in front of the gates—that varied greatly in plan (round or polygonal), building material (stone or earth), and makeup (solid or with gun chambers inside). The bastion crucially differs from both the artillery tower and the bulwark in being a solid, earth-filled platform projecting from the walls, with a pointed polygonal plan to eliminate blind spots in the defensive fire plan. Guns mounted on its faces fire outward, while guns on its flanks sweep the adjacent curtain walls. Here the term bastioned system will be used only for those bastioned enceintes that are designed in such a way as to enable neighboring bastions to defend each other through reciprocal flanking fire. This implies that the bastions are not too far apart and that each one has its two faces precisely aligned with the gun positions in its neighbors' flanks.
From Bono to Van Noyen
Prior to Olgiati's visit in 1553, most fortifications in the Low Countries were designed by Donato de Bono (d. 1556), a native of Bergamo who was possibly an apprentice of Michele Sanmicheli. After his move to the Low Countries in 1540, Bono became the emperor's principal engineer there and the author of nearly all new fortifications. Between 1540 and 1553 he worked on more than thirty sites, for which he designed some seventy-five bastions. His record includes two citadels (Ghent, Cambrai), a fortress town (Mariembourg), a fortified castle (Renty), a coastal fortress (Rammekens), and the famed city walls of Antwerp (Figure 1). In addition, Bono partially modernized the walls of at least twenty towns. He was neither the first nor the only Italian engineer in the Low Countries in this period, but he was by far the most productive, and although several bastions had been built there in the 1530s, it was Bono's work of the 1540s that embodied the spread of the new fortification method throughout the Low Countries. When Olgiati arrived in 1553, his task was not just to plan new fortifications but also to review the ones built by Bono.
Olgiati was entrusted with another task as well: to initiate a local architect into the art of fortification design. New evidence reveals that during his tour through the Low Countries, Olgiati was always accompanied by Sebastian van Noyen (1523–57). Van Noyen was a young architect from Utrecht, recently engaged as engineer by the central government. Until 1553, Van Noyen had worked as architect for Antoine Perrenot de Granvelle (1517–86). Granvelle, bishop of Arras (and later cardinal), was the powerful secretary of state to the emperor and a distinguished art patron. Upon Granvelle's instigation, Van Noyen visited Rome around 1550, where he made a meticulous survey of the Baths of Diocletian; his drawings were subsequently turned into a monumental set of etchings published by Hieronymus Cock in Antwerp in 1558—the first systematic record of such a building to appear in print.9 Van Noyen was also the likely architect of Granvelle's palace in Brussels. Designed around 1551 and modeled in part on the Palazzo Farnese in Rome (drawing particularly on Michelangelo and Vignola's recently built courtyard arcades and windows), this was one of the earliest and most purely Roman Renaissance–style buildings in the Low Countries.10
In December 1552, Van Noyen participated in the ill-fated siege of Metz by the imperial army and thereupon entered the service of the central government as a military architect. He had little experience in fortification, however, so the authorities arranged for the best available expert to teach him the latest fortification methods. Not coincidentally, the emperor sent for Olgiati at the same moment he engaged Van Noyen as engineer, in February 1553. Thus, it was from Olgiati that Van Noyen soon received his training in fortification design.
Van Noyen's familiarity with Italy, his expertise in surveying large-scale buildings, and his connections (through Granvelle) at the Brussels court made him an ideal intermediary between Olgiati and the Netherlandish master builders and government officials. Following Olgiati's return to Italy, Van Noyen became Charles V's (and, after 1555, Philip II's) chief engineer in the Low Countries. He designed all the major fortifications of the mid-1550s, including the new fortress towns Hesdinfert, Charlemont, and Philippeville, which brought him praise from Lodovico Guicciardini and Giorgio Vasari.11 Sebastian van Noyen's career ended abruptly in 1557 with his unexpected death at age thirty-four. He was succeeded by his nephew Jacob van Noyen, who was supposed to undergo the same initiation as his uncle before him: Jacob, too, was a novice in fortification design at the start of his government employment and was likewise expected to be trained by an accomplished Italian engineer—in his case, however, this never happened.12
Olgiati's tour in the Low Countries was not exceptional in itself. At least twenty Italian engineers are known to have worked there between 1533 and 1559, and most stayed only for short periods—often less than a year.13 Almost all came from Northern Italy, and several were recruited, like Olgiati, from the Duchy of Milan, which belonged to the Habsburg realm. Tours of inspection featuring an Italian engineer and a local architect were common practice. Precedents include Jacopo Seghizzi (alias Frate da Modena) and Jehan Lartésien in Hainaut and Artois in 1533–34, Baldassare Avianello and Marcelis Keldermans in the Utrecht region in 1540, Donato de Bono and Lartésien along the entire southern border in 1540–41, and Bono and Willem van Noort in Hainaut in 1546.14
Among these, however, the tour by Olgiati and Van Noyen in 1553 stands out, not only because it is so well documented but also because it marked a turning point. The fortifications designed after Olgiati's visit differed profoundly from those built before and were, moreover, authored by Netherlandish rather than Italian engineers. After 1553, Bono, whose work came in for serious criticism, did not receive any more important commissions. All the big projects now went to Sebastian van Noyen, and the fortifications he designed in the mid-1550s owed much to his mentor, Olgiati (Figure 2). Even in the 1560s, Sebastian's successor Jacob van Noyen still worked in the manner of Olgiati. Only in 1567, with the arrival of the Duke of Alba and the erection of the Antwerp citadel by Francesco Paciotto, was there a notable change in fortification practice. The development of military architecture in the Low Countries during these crucial decades can therefore be divided into a “Bono period” (1540–52) and an “Olgiati/Van Noyen period” (1553–67). The shift between the two is examined here.
Olgiati and Van Noyen's Tour: A Reconstruction
Available evidence allows us to reconstruct Olgiati and Van Noyen's tour in the Low Countries in unprecedented detail (Figure 3). This helps explain their working method and use of drawings. It also elucidates how Italian engineers and local architects collaborated—a key mechanism of transcultural exchange in Renaissance Europe.
Charles V held Olgiati in high esteem and had long wanted to employ him in other parts of his empire. The emperor likely became familiar with Olgiati's work during his stay in Genoa in 1536 and his visit to Milan in 1541.15 In the late 1540s, the governor of the Duchy of Milan, Ferrante Gonzaga, regularly informed the emperor of Olgiati's whereabouts and sent him drawings and reports in Olgiati's hand. But Charles's repeated requests to send Olgiati on missions further afield—to Vienna in 1547, to Sardinia and the Balearic Islands in 1550—met with refusals from both Gonzaga, who objected that Olgiati's expertise would be missed in Milan, and Olgiati himself, who complained that he was too old and worn-out to be making long journeys outside his homeland.16
In June 1551, Charles's son Philip (then Duke of Milan, later King Philip II of Spain) visited Milan. He was taken on a guided tour of the city walls and expressed his admiration for Olgiati's project for the new enceinte. Philip asked for and was given a copy of the closely guarded plan of these new fortifications.17 It is unlikely that Philip and Olgiati (then with the army in Parma) met on this occasion, but the episode amplified Philip's and Charles's esteem for Olgiati's work. A few months later, following his return to Madrid, Philip wrote to Gonzaga that he wanted Olgiati (or, if need be, another engineer of similar merit) to come to Spain. Olgiati again refused, and it was his junior collaborator, Giovanni Battista Calvi, who left for Spain in 1552.18 Calvi stayed on the Iberian Peninsula until his death in 1565 and had a successful career as an engineer in service to the Spanish crown. His work was fundamental for the development of military architecture in Spain; in fact, Calvi's role in Spain was comparable to that of Olgiati in the Low Countries.
In February 1553, Gonzaga and Olgiati finally received an order they could not refuse. At the insistence of Mary of Hungary, Charles V ordered Gonzaga to send Olgiati to the Low Countries immediately.19 This directive was provoked by the raging border wars against France, in which the emperor had suffered heavy territorial losses, and was motivated also by the central government's dissatisfaction with Bono's recent work.20 Gonzaga and Olgiati had no choice but to comply, and by the end of March the engineer was ready to leave for the Low Countries.21
Olgiati arrived in Brussels on 26 April 1553.22 After paying a visit to the Venetian ambassador, he presented a letter of recommendation to Granvelle, who then introduced him to Mary of Hungary. She informed Olgiati that his mission would involve inspecting border towns. On 5 May Olgiati was still in Brussels, but soon after he left for Luxembourg and Thionville.23 Both cities were in urgent need of fortification, as one year earlier three nearby strongholds (Yvoix, Damvillers, and Montmédy) had been lost to the French. At the time, Sebastian van Noyen was working in the Luxembourg area, where he had been since February.24 This was his first mission as engineer.25 He met up with Olgiati, and the two set off together for six months. Olgiati's plan for Luxembourg has been preserved, but nothing is known of his contribution in Thionville.26
From Luxembourg, Olgiati and Van Noyen next went to Maastricht. The plan Olgiati drew there is dated 18 May (Figure 4).27 His assistant, Evangelista (brought from Milan), broke his leg in Maastricht and was replaced by another assistant for the remainder of the tour.28 Building accounts indicate that Van Noyen was with Olgiati in Maastricht and that the fortification plan they made there amended an earlier design by Bono.29 The two engineers stayed in Maastricht until early June. On 4 July, the Maastricht city council affirmed that all works on its fortifications were halted because a certain “master of works” sent by Mary of Hungary (Olgiati or Van Noyen) had made a new plan, which needed to be approved in Brussels.30
The arrival in the Low Countries of the illustrious Milanese engineer, also a renowned artillery officer and expert in siege techniques, reached the ears of the imperial army, which was then laying siege to Thérouanne, in Artois.31 The Spanish soldiers, who described Olgiati as “the best man in the world,” begged Mary of Hungary to send the engineer to their camp so that he could advise on the difficult siege works.32 Mary replied that she could not send Olgiati to Thérouanne, as he was busy in Maastricht.33 He would not have arrived in time anyway, for Thérouanne fell the next day.
By mid-June Olgiati was back in Brussels. He once more complained of being too old for constant travel, and he asked Mary of Hungary if he might return to Italy.34 But the engineer was immediately sent off again with Sebastian van Noyen, this time on an extensive tour of inspection along the southern border starting with Mariembourg. On 13 July, Olgiati and Van Noyen received a laissez-passer from the emperor giving them unhindered access to all fortifications in the border region.35 Additionally, Mary of Hungary wrote personal letters to the local governors and captains to announce the engineers' arrival and emphasize the importance of their mission.36 By around 23 July, Olgiati and Van Noyen were in Mariembourg, where they criticized Bono's design and drew up a plan showing their amendments (Figure 5).37
After Mariembourg the engineers visited nearby Fumay, a small town occupying a strategic position near the French border, in a bend of the Meuse. Because of the war, this was dangerous territory, and the captain of Mariembourg had to accompany the two engineers to Fumay with an armed escort.38 Fumay lacked modern fortifications, so here for once Olgiati and Van Noyen were tasked not with improving existing works but with designing a new fortress. The result of their excursion to Fumay is not known.39
From the Sambre and Meuse region Olgiati and Van Noyen set off westward toward Hainaut and Artois. After Fumay they possibly visited Avesnes, Landrecies, and Le Quesnoy. By 12 August they were at work in Mons, where they changed, in situ, the layout of the bastion at the Porte de Nimy. The first stone of this new bastion, designed by Bono, had been laid barely two months earlier. Using sticks and ropes, Olgiati and Van Noyen “remedied the badly begun bastion” by tracing a new outline on the ground.40 Van Deventer's later plan of Mons confirms that the bastion built at the Porte de Nimy bore the stamp of Olgiati, not Bono.41 The plan that Olgiati and Van Noyen drew up in Mons is lost, but it was probably comparable to the later plan by Mario Brunelli (discussed below).
After Mons, the engineers visited Valenciennes, Bouchain, and Cambrai in quick succession. Olgiati's plans of these three places are dated 20, 22, and 24 August, respectively (Figures 6 and 7).42 They next went to Bapaume, Arras, and Aire (Figures 8, 9, and 10).43 Around 9 September the engineers arrived in Renty (see Figure 7).44 They probably also visited Saint-Omer, Bourbourg, and Gravelines around this time.
While Olgiati and Van Noyen were crossing Hainaut and Artois, the imperial field army was still campaigning there. The army had just completed two successful sieges: on 20 June Thérouanne was captured, and on 18 July, Hesdin. Both strongholds were subsequently razed. Thérouanne's fortifications were dismantled in July and its last remains destroyed by gunpowder mines in mid-August. The castle of Hesdin was similarly destroyed during the first days of August.45 When Olgiati and Van Noyen passed through the area at the end of August, the demolition in these places was finished. They possibly visited the smoldering ruins of Thérouanne or Hesdin along their route, but, unlike Bono, sent to Thérouanne in early July to advise on the destruction of its fortifications, they cannot have played a significant role in the demolition work. It is possible, however, that Olgiati made a first design for the new fortress town that was to replace Hesdin.46
That Olgiati and Van Noyen were in the middle of a war zone helps to account for their fast pace: French troops were approaching. Indeed, the engineers had only just left Cambrai and Bapaume in late August when these two border towns were threatened with siege. Early in September, French troops led by Henry II marched on Bapaume and Cambrai and then on to Bouchain and Valenciennes. Neither a siege nor a battle developed, however, and three weeks later the French withdrew again.47
At the end of October, Olgiati traveled to Namur, again accompanied by Sebastian van Noyen, who brought a drawing of the castle of Namur with him.48 Early in November Olgiati and Van Noyen returned to Brussels to present their design for the castle's fortifications to the Council of Finance.49 Shortly afterward, Olgiati returned to Italy. He was back in Milan around December 1553.50
Thus, between May and November 1553, Olgiati and Van Noyen inspected at least fourteen sites in the Low Countries, and they almost certainly visited still more places along their route (see Figure 3). For ten places extant drawings can be linked to their visits, and five of these are signed and dated by Olgiati; for eight places his intervention is substantiated by other archival documents. With the exception of Maastricht, Olgiati and Van Noyen's expeditions concentrated on the southern border, their route dictated by the ongoing military campaigns. The pervasive threat of a French attack imposed a high work rate, and this in turn helps explain the engineers' particular use of drawings. To save time they made extensive use of existing plans. Understanding their working method is essential to interpreting these documents correctly.
The Use of Drawings and the Plans in the Turin Atlas
Olgiati's drawings all share the same formal characteristics. First, he outlined the plan of the existing fortifications in red, and then he superimposed his own project in black (or dark brown) ink.51 Typically, he showed only a ground plan, his drawing of Valenciennes being the only one to include a vertical section of the planned ramparts (see Figure 6). He annotated his drawings copiously, with measurements, technical remarks, and topographical comments. Two of the plans not signed by Olgiati (Mariembourg and Arras) contain notes in Dutch and French as bastardized by a Dutch speaker; these can be attributed to Van Noyen. The plan of Luxembourg, on the other hand, has Italian inscriptions not in Olgiati's hand—possibly a copy made by his assistant. That such copies were made is proven by the plan of Cambrai, of which both Olgiati's original and a copy survive. Likewise, the anonymous plan of Bapaume is evidently a simplified copy of a lost Olgiati original. Important here is not the distinction between original and copy or the issue of authorship but the fact that all these drawings share certain characteristics. All are artifacts of the same working method.
When the engineers arrived at a site, their first task was to inspect the existing fortifications. One way of doing so is illustrated by a previously unknown drawing of Saint-Omer held in the Vatican Library, the result of a survey made on-site (Figure 11).52 On one side of the sheet are several profile views of the town walls, and on the other is an accurate plan of the circuit of the walls. The contours of the fortifications are drawn in a simple line; additional hatching indicates the earthen ramparts while watercolor accentuates the water in the ditches and rivers. All lines are executed in the same brown ink, without color coding. Measurements indicating widths of ditches, heights of ramparts, and lengths of walls were likely made on the spot. Both the ground plan and the profile views bear inscriptions, all in Dutch, describing in detail the site's topography and the state of the fortifications.53 There is no indication of any planned works; this is purely a record of the existing situation, datable to the early 1550s.54 Dating and inscriptions connect the drawing to Sebastian van Noyen, who possibly made it during his tour with Olgiati in 1553.55
Carrying out such a survey took time, while evidence indicates that the two engineers traveled fast, staying no more than a couple of days in each place, a single day in some cases.56 Although it is not certain that they drew and dated all plans in situ, it is clear that Olgiati and Van Noyen inspected many sites within a short time span. This fast pace implies that they themselves did little time-consuming surveying work on-site. Yet the outlines of existing fortifications, drawn in red on their plans, are without exception accurate, indicating that they had reliable plans of the current fortifications at their disposal.57 Olgiati could then simply copy those plans onto his sheet before adding his own modifications and comments.58
The plans given to Olgiati by the central government were likely Bono's. Not one of Bono's drawings has been preserved, however, and none of the plans given to Olgiati and Van Noyen survives. But it now appears that copies of these lost plans do exist in an atlas in the Biblioteca Nazionale in Turin.59 Among the many unidentified fortifications in the BNT atlas are those of at least twenty-two different places in the Low Countries—mainly fortified towns along the southern border (see Figure 3). The plans show only the defensive perimeters, drawn in red, without any indications of streets, buildings, or topographical elements. Most of the plans include scale bars and compass crosses, but they lack inscriptions—even the place-names have (with two exceptions) been omitted. The places can be identified, however, through comparison with later fortification plans and with Van Deventer's town plans.
The plans in the BNT atlas have two important characteristics: first, most represent the state of fortifications around 1552; and second, they correspond exactly with the red outlines on Olgiati's drawings.60 In every instance the red outline on Olgiati's drawing matches up with the corresponding plan in the BNT atlas, to the extent that these plans must be copies (Figure 12).61 The red outlines on Olgiati's drawings and the plans in the BNT atlas were not copied directly from one another, however, but from common originals that are now lost. In some cases the copies have the same dimensions, but most of the plans were reduced or enlarged in the copying process: Olgiati's plans for the bigger cities—Maastricht, Valenciennes, and Arras—are much larger than the corresponding plans in the BNT atlas.62 The precision with which such rescalings were done is remarkable. When a plan was reduced or enlarged, its proportions were precisely preserved, and few or no details were lost. This points to the use of advanced drawing instruments.63 That the rescaling of such plans was current practice is illustrated by the drawing of Mariembourg (see Figure 5). This sheet confusingly shows the same ground plan twice, but on different scales: a neat copy in pen and brown ink and a smaller version in black and red chalk.64 As fortification plans were frequently copied, adjusted, and recopied, questions of authenticity, authorship, and dating of extant drawings must always be approached with circumspection.
The anonymous plans in the BNT atlas are not design drawings but records of the existing situation. They reflect, more precisely, the state of fortifications in the year 1552, or thereabouts. That makes this collection of plans the oldest of its kind, and for many of the towns concerned, the earliest plans yet known are those in this atlas. As such, these plans are a fundamental source for the study of urban history in the Low Countries, even if they show nothing more than the contours of the towns' fortifications. They are also relevant for the history of urban cartography, showing that by 1550 the central government possessed accurate, orthogonal plans of many towns (or at least of their defensive perimeters), and that if the need arose these could be rescaled and copied for other purposes. Consequently, the earliest town plans of the Low Countries—notably those of Jacob van Deventer, commissioned by Philip II in 1558—were not necessarily made from scratch, as is commonly supposed; rather, many were preceded by and possibly based in part on existing fortification plans.65
A Panorama of the Low Countries' Border Fortifications ca. 1550
The plans in the BNT atlas offer a reliable and coherent picture of the state of the Low Countries' border fortifications in the middle of the sixteenth century. With two exceptions (Maastricht and Wageningen), the plans all concern towns along the southern border, mostly in the provinces of Artois and Hainaut. They reveal that around 1550 most of these towns, despite their vulnerable location near the French border and despite the large-scale fortification campaigns of the preceding decades, still relied mainly on their outdated medieval walls. Only four places already possessed fully bastioned enclosures: the little town of Bouchain, the fortress town of Mariembourg, the citadel of Cambrai, and the fortified castle of Renty (Figure 13). These were all small entities, and in each case the enceinte was a simple square with four corner bastions. In contrast, none of the larger towns had yet been equipped with modern fortifications around the entire perimeter. Instead, medieval walls were merely reinforced with bulwarks in front of the gates and a couple of bastions at the most. Only a few towns close to the border, such as Le Quesnoy, Avesnes, and Yvoix, already possessed four or more bastions (or bastion-like works). Most towns, including Gravelines, Bourbourg, Saint-Omer, Aire, Arras, Valenciennes, and Luxembourg, counted only one or two bastions, and some cities, such as Lillers, Mons, and Maastricht, had none at all (Figures 14, 15, and 16).
Thus, as of 1550, bastioned systems did not yet exist in any of these towns.66 It is often assumed that when a town's fortifications were modernized, medieval walls were replaced by a new enceinte with straight curtain walls and regularly spaced bastions. But this enormously expensive solution, as seen in Antwerp, was highly unusual.67 As the plans in the BNT atlas show, existing fortifications were usually not replaced in one fell swoop but adapted a little at a time. Such gradual, step-by-step transformation produced not a coherent whole but a heterogeneous amalgam of varied defensive works. The regular fortress cities that feature so prominently in the literature are not representative of the first generation of fortified towns realized after the birth of the bastion; almost all such towns had highly irregular plans that testify to the complicated development of their fortifications.
This is true not only for the enceinte as a whole but for the individual defensive works as well. The plans in the BNT atlas depict many strikingly irregular bastions. Their erratic shapes were sometimes caused by a town wall's irregular circuit, but more often they were the consequence of complex building histories. The first bastions in the Low Countries were rarely built entirely ex novo. Most were realized through the adaptation of preexisting structures such as gun towers or bulwarks, with substantial remains from the older constructions incorporated into the new work. It is therefore not always meaningful to make a sharp distinction between an old-fashioned bulwark and a modern bastion. Moreover, some of the defensive works conceived by local master builders in the first decades of the sixteenth century were typologically similar to the bastions that the Italian engineers designed in the 1530s and 1540s.68 The introduction of the bastion in the Low Countries was not a radical break with local tradition but a step in an already ongoing process. Tellingly, contemporaries continued to use the old term bulwark (bolwerck, boulevard, and so on) for the new variant, which only in the next century came to be called a bastion.69
The group of plans in the BNT atlas also shows that there was no standard bastion type used everywhere as a passe-partout solution. In total, more than forty bastions (or bastion-like works) are recorded on these plans, and they display a bewildering typological diversity. The plan of Avesnes, for example, shows no less than six irregular bastion-like works, all different, each evidencing the transition from irregular bulwark to pentagonal bastion (see Figure 14). The plan of Bouchain depicts four bastions, but each with a different ground plan (see Figure 13): the somewhat anomalous Ostrevant bastion was already completed in 1534–39, probably to a design by Jacopo Seghizzi; the other three bastions were built in 1541–48 to designs by Bono, but even these bear significant differences among them.70
By around 1550, most border towns were fortified with isolated, self-sufficient bastions that did not provide reciprocal flanking fire. Clearly, the architects aimed not to establish an overall defensive scheme but to remedy weak spots by adding solitary bastions to the walls nearby. Individual bastions operated as isolated units fending for themselves. Accordingly, the designs of such bastions were determined by their locations, not by their relationship to other bastions. This is obvious for towns with only one bastion, such as Arras and Bourbourg, but it holds also for towns that had two or three bastions, such as Aire and Béthune (see Figure 15). In each case the bastions were solitary installations defending only a section of the walls and not adjusted to one another.71 Not one of these town plans evinces any intention of creating an integrated defensive system, let alone a regular enceinte. Nowhere are the fortification works coupled with any urban expansion, or even with any adjustment of the existing circuit of the town walls.
Thus, by the early 1550s, two decades after the appearance of the first bastions in the Low Countries, the government's huge building campaign aimed at modernizing its border fortresses was still far from complete. The plans in the BNT atlas document not just the progressive spread of bastioned fortifications from the 1530s onward but also the survival of defensive works built in previous decades, of which other visual evidence is extremely rare (Figures 17 and 18). The plans are therefore an invaluable record of the typological evolution of these works, from the irregular bulwarks of the 1510s and 1520s through the protobastions of the 1530s to the mature bastions of the 1540s and early 1550s.
Round bulwarks can be seen on the plan of Douai (see Figures 16 and 18). They were erected in front of the city gates and detached from the walls. Built in the late fifteenth and early sixteenth centuries, they all have a semicircular or horseshoe-shaped plan and remained virtually unchanged until the 1550s, by which time they were severely outdated.72 Yet even as late as the 1540s, such round bulwarks were still being commissioned: the plan of Maastricht shows the horseshoe-shaped ground plan of the Sint-Maartensbolwerk (1542–47), which for its time was a decidedly old-fashioned type of defensive work.73 Polygonal bulwarks appear on many plans. That of Arras includes two well-documented ones, built at the Porte Méaulens (1508–13) and the Porte Saint-Nicolas (1513–16) (see Figure 12). Both were transformed into bastions in the mid-1540s by having been filled with earth (while maintaining their function as city entrances); this plan shows that their original ground plan, known from an earlier drawing, was not changed in the process.74
Several plans depict what look like mini-bastions (see Figure 18). These small bastion-like organs are actually moineaux or caponiers (small flanking constructions in the ditch) in the shape of bastions. Two examples can be seen on the plans of Maastricht and Douai; for both towns' fortifications, this feature is the only sign of modernity. Another small bastion-like moineau from around 1535 can be recognized on the plan of Saint-Omer, situated between two normal (and later) bastions.75
The plans also depict some of the first bastions built in the Low Countries, probably to designs made by Jacopo Seghizzi in 1533–34. These include the Croÿ bastion (1533–34) in Le Quesnoy, the bastion de la Reine in Avesnes (1534–38), and the Ostrevant bastion (1534–39) in Bouchain (see Figures 13 and 14).76 The plan of Valenciennes reveals the irregular ground plan of the Cardon bastion (1533–36) (see Figure 17).77 Most of the other bastions recorded on these plans were built to designs by Bono between 1540 and 1552.
The plans in the BNT atlas compel us to revise the accepted dating and attribution of several bastions. For example, the four bastions seen on Van Deventer's town plan of Aire are commonly dated to the 1540s and attributed to Bono. Yet two of them are conspicuously absent on the BNT plans; this implies that these were actually begun after 1552 and must be attributed to Olgiati or Van Noyen.78 The same is true for the two bastions in Mons that appear on Van Deventer's town plan but not on the plan in the BNT atlas. In each of these cases this new dating finds confirmation in the general shape of the bastions: those begun after 1552 are all considerably larger than the ones built before then. Indeed, the small size of Bono's bastions was one of Olgiati's main criticisms of them.
Olgiati's Designs: From Defenses with Bastions to Bastioned Systems
Olgiati's proposals comprise both amendments to existing fortifications and designs for new works. His amendments mainly concern the shape and size of the bastions and the position of the gates. He found the existing bastions much too small, lacking space for the necessary guns in their flanks and up on their platforms.79 Other experts shared Olgiati's opinion. In June 1552 the Venetian engineer Giovan Tommaso Scala criticized two fortresses in the province of Luxembourg that had been easily captured by the French despite new fortifications; he proposed to enlarge the fortresses' bastions.80 Francesco de Marchi, too, considered the bastions of the 1540s too small. On a visit to Jülich in 1556 he praised Pasqualini's new citadel (1547), which he called a “beautiful and perfect square fortress,” but to his surprise the bastions were so small (“piccolini”) that they could barely support two pieces of artillery.81 From 1550 onward military architects realized that the bastions built thus far were not large enough.
Olgiati did not simply enlarge the bastions but drastically changed their composition so as to increase both their resilience and their firepower. He added round orillons to their sides in order to better shield the gun positions in the retracted flanks against enemy fire; he substituted the casemates (vaulted gun chambers) in these flanks for open-air terraces; and he added cavaliers behind the bastions—high earthen platforms on which additional guns could be deployed for long-range fire (Figure 19). These adjustments demonstrate Olgiati's awareness of the increasing impact of siege artillery. The first bastions had been an effective response to how sieges were conducted in the 1520s and 1530s, but by the 1550s artillery pieces had grown significantly in both number and effectiveness.82 Larger bastions were therefore needed, and optimal flanking became vital.
The location of gates was another critical matter. In Bono's designs a gate was always positioned next to a bastion, in a recess in the wall to conceal it from enemy fire. This arrangement was comparable to the traditional combination of gate and bulwark. Its disadvantage was that the gate was covered by one bastion only. Where possible, Olgiati therefore moved the gate to the middle of the curtain wall, so that it could be defended by two bastions.83 In this respect it is noteworthy that in May 1553 it was decided that the gate of the citadel of Ghent would be relocated because it was situated too close to the bastion.84 There is no evidence that Olgiati visited Ghent in this period, but this decision points to his influence.
Olgiati's principles for the design of new fortifications are most clearly illustrated by his drawings of those cities for which he planned new bastioned enceintes: Maastricht, Valenciennes, and Arras (see Figures 4, 6, and 9). All three designs employ the same precepts, which can be summarized as follows. To begin with, Olgiati does not combine the modernization of the city walls with any kind of urban expansion. He keeps the existing perimeter in place (or reduces it), although irregular sections in the circuit are straightened out as far as possible. Thus, about half to three-quarters of the existing circuit wall is retained to serve as the outer wall of the new ramparts, while the rest is marked for demolition to make room for new, straight sections.85 Olgiati also modifies the gates. He proposes to tear down the existing and often imposing gate buildings and adjacent defensive organs and to replace them with simple, unfortified entrances—little more than framed passages through the ramparts. The entrances to a city had always been among the most heavily fortified parts of the enceinte, but here their defense is left entirely to the adjacent bastions. (Olgiati does not change the position of the entrances, however; apparently he thought it a step too far to modify existing street patterns.) He then furnishes the rectified enceinte with new bastions. These he places more or less equidistant from each other, approximately 300 meters apart, within range of each other's artillery. A bastion is placed on every corner of the perimeter with additional ones between, resulting in a total of ten bastions for Valenciennes and twelve for Maastricht and Arras.
In all three drawings these new, large bastions have round orillons concealing deeply retired flanks with low-lying open-air gun terraces for flanking fire.86 The bastions' earthen mass functions as a vast artillery platform for long-range fire while supplementary cavaliers stand on each corner. Where possible, the bastions are furnished with underground countermine galleries.87 All of these bastions are similarly designed, yet they have different shapes because their ground plans are determined by concern for mutual flanking fire. This explains why the bastions on the corners of the perimeters all have sharp points, while the bastions in between have obtuse or flat fronts. A few bastions are of deviant design due to irregularities in the circuit of the walls; in other cases deviant forms result from the incorporation of preexisting bastions or bastion-like structures.
It is noteworthy that Olgiati preserves few of the existing works. In the plan for Arras, for example, he incorporates one of the five early sixteenth-century bulwarks into his new bastioned enceinte but eliminates all the others.88 He also keeps the one existing bastion (the Rœulx bastion, built in 1542–46 to a design by Bono) but substantially enlarges it: he retains only its faces, while its flanks are to be rebuilt (see Figure 19). In the plan for Valenciennes, Olgiati integrates the two existing bastions into the new scheme, while removing all the gates and adjoining bulwarks.89 An even more radical change occurs in the westernmost part of the city, on the left bank of the Scheldt near the old Château-le-Comte—the most well-fortified part of the city. In 1525–33 a large horseshoe-shaped bulwark had been built there, in front of the Porte d'Anzin.90 Olgiati, however, proposes to cut off this quarter to improve the general layout of his fortifications, arguing that this part of the city is commanded by a nearby hill.
In sum, Olgiati's military architecture was fundamentally different from that of Bono. The difference lay not so much in the design of the bastions themselves but in how the bastions now flanked each other and formed part of an integrated scheme. Adding a few individual bastions was no longer considered enough to fortify a town; rather, an overall bastioned system was required. This was an altogether new concept of fortress building, employing a regular plan in which all bastions were linked within a larger whole. To function properly, this integrated system had to be realized in its totality, for any individual bastion could operate correctly only when it had two equally operational neighbors. This entailed a different approach to fortification planning. In the 1540s individual bastions were added where necessary, while the existing circuit of the walls remained unchanged. Olgiati's system, by contrast, demanded a regularization of the enceinte and the construction of several bastions simultaneously. This raises the question as to what extent Olgiati's plans were actually executed.
Outcome, Influence, and Significance
It is difficult to know whether many of the minor improvements Olgiati proposed for existing fortresses were carried out. The amendments he suggested in Cambrai, Renty, and Bouchain were largely ignored.91 The outcomes of his designs for large-scale new enceintes are easier to assess: these were far too ambitious and costly and were nowhere realized in their entirety, although in subsequent years a few bastions were added here and there in accordance with Olgiati's plans.
In Maastricht the implementation of Olgiati's scheme remained limited to the construction of one bastion. It was begun in 1554 and can be attributed to Sebastian van Noyen, but its location and its composition (with its large size, obtuse front, and retired flanks behind round orillons) correspond exactly to Olgiati's plan.92 After the completion of this first bastion, however, the works in Maastricht came to a halt for more than two decades. In Valenciennes not one of Olgiati's new bastions was executed; the works there were limited to completing the already begun Montois bastion. In Bapaume a more substantial part of Olgiati's plan was carried out: the Egmont bastion, erected on the northwest corner of the town wall, was probably begun in 1554 by Sebastian van Noyen; around the same time one of the existing bastions, built by Bono in the 1540s, was reinforced with round orillons; and later, the Lannoy bastion was added on the east side of the town.93 All three interventions correspond with Olgiati's plan.
In Arras the existing fortifications were maintained, although two bastions were added later: the Marles bastion in the west and the Saint-Michel bastion in the east. Begun around 1560 and completed in the 1580s, they can be attributed to Jacob van Noyen, yet in their location and ground plan they correspond to Olgiati's plan of 1553.94 Documents from 1560 confirm that the Saint-Michel bastion was built “according to the plans of the engineers Jean Mary [Olgiati], former collaborator of the late Sebastian, and Jacob van Noyen.”95 This proves that even several years after his visit, Olgiati's designs still served as master plans.
These examples demonstrate the immediate effect of Olgiati's visit: parts of his plans were carried out in subsequent years, especially by Sebastian van Noyen and, after 1560, Jacob van Noyen. But Olgiati's influence went beyond the works he planned himself; it also manifested itself indirectly in two ways. First, the new fortifications the Van Noyens designed after 1553 were clearly indebted to Olgiati's principles. Sebastian's plans of 1554–55 for the fortresses of Hesdinfert, Charlemont, and Philippeville all show similarities to Olgiati's manner, from the layout of the bastions and the cavaliers behind them to the disposition of the gates.96 These “Olgiatian” features are recognizable also on a newly discovered perspectival design drawing for Philippeville attributable to Sebastian van Noyen (Figure 20; see Figure 2).97 The same principles are adopted in a pair of alternative designs for the expansion of Thionville, attributed to Jacob van Noyen, dating from around 1561 (Figure 21).98
Second, Olgiati's influence can be seen in the designs of at least two of the Italian engineers who worked in the Low Countries after Olgiati's visit. Francesco Thebaldi and Mario Brunelli both arrived in the Low Countries in 1554, shortly after Olgiati returned to Milan. Thebaldi (or Tibaldi) came from Mantua and was an assistant to Olgiati.99 Of Brunelli, neither his origins nor his relation to Olgiati is documented, but his familiarity with Olgiati's work is evident.100 Like Olgiati, Thebaldi and Brunelli worked mainly on the southern border fortresses. Thebaldi stayed in the Low Countries for eight months, from September 1554 to April 1555. His only documented work concerns Gravelines. After his return to Italy, he worked under Olgiati's direction in Novara and Cremona. Brunelli stayed much longer in the Low Countries, from April 1554 to October 1557, but little is known about his activities. He developed a plan to flood Mariembourg, recently captured by the French, and worked on the fortifications of Mons and Cambrai.101 Later he was employed to direct the construction of trenches and temporary field fortifications.
Both Thebaldi's plan for the fortification of Gravelines and Brunelli's for the fortification of Mons show striking similarities to Olgiati's drawings (Figure 22). In both cases the existing fortifications are shown in red outlines, which match with the corresponding plans of Gravelines and Mons in the BNT atlas. Brunelli's plan of Mons shows a vertical section through the rampart, just like Olgiati's plan of Valenciennes. Both Thebaldi's and Brunelli's projects conform to Olgiati's principles, from the overall defensive scheme to the composition of the bastions and the adjoining cavaliers. Thebaldi and Brunelli may have based their plans on drawings Olgiati made during his tour in 1553, or they may have created their own designs using the master's method. Either way, Olgiati introduced new design principles and practices to the Low Countries in 1553, and these were adopted by other engineers, locals as well as Italians.
After the arrival of Bono in 1540, Olgiati's visit to the Low Countries in 1553 marked a second turning point in the development of military architecture there. His designs differed fundamentally from Bono's and had a lasting effect on fortification practice. In the preceding two decades (1533–53), fortifying a town had involved little more than adding a few small, isolated bastions that did not link to form a defensive system. Bastions were simply attached to existing town walls, which remained otherwise unchanged. Often an older gun tower or bulwark stood on the spot where a bastion was required, in which case the existing structure was remodeled into a bastion-like structure, usually of irregular shape. This pragmatic approach gave the individual bastions and the fortifications as a whole a heterogeneous appearance. In this regard it must be emphasized that the regular bastioned enceintes of Bono's best-known achievements—the Ghent citadel, the Antwerp city walls, Mariembourg—were not representative of the many border towns he fortified in this period; their enceintes were disparate conglomerations of various defensive works, including only a few new bastions.
The bastions built after Olgiati and Van Noyen's tour were not only different in shape and size, but also their siting and layout were now interrelated so as to enable reciprocal flanking. It is only after this critical step that one can speak of a full bastioned system. Instead of merely modernizing existing fortifications, Olgiati provided master plans for the construction of entirely new, coherent, and uniform bastioned enceintes, proposing to relocate existing walls and gates as needed. Still, with only a few of his designs carried through to completion, most of the fortifications he worked on remained inchoate in form, seemingly comparable to Bono's piecemeal legacy. For Bono, however, the existing town wall dictated the location and form of each new bastion. For Olgiati, the envisaged bastioned system would reshape the existing urban fabric. This new, more comprehensive approach had a far greater impact on urban development than the modest cobbling together of defensive works practiced by Bono and others before the early 1550s. Indeed, scholarly debates on the origins of the bastion notwithstanding, this shift—from bastions to bastioned systems—was ultimately of greater significance for the history of urban planning than the appearance of the first bastions in the 1530s.