Holy War in Ibn Khaldūn: A Transcultural Concept?^† 

In the Muqaddima, Ibn Khaldūn conceptualises war as something natural to the human being (amr ṭabī‘iyy fī-l-bashar), from which no nation or generation has been able to escape. In his opinion, it occurs most of the time due to jealousy and rivalry (ghayra wa munāfasa). The cause of this, in general terms and depending on the case, is either hostility, zeal in the defense of God and His religion (ghaḍib^an li-Llah wa li-dīni-hi), or the eagerness to obtain power and the desire to establish it.¹² 

Based on these statements, the North African thinker establishes four types of war. The first type is the one that occurs between neighboring tribes or rival clans. The second one generally takes place between savage peoples that inhabit desert and desolate areas (al-qafr) and obtain their sustenance with their arms. The third one is the call to jihād by divine law (Sharī‘a), the war for religion or the religious spread through arms. This is an interesting idea, since it illustrates well how the Islamic World considered the notion of jihād over centuries: rather than being only a religious justification of violence, it is understood as a legal problem and made more precise in law compendia where certain points were treated in depth. Examples included who had to participate in the jihād, what had to be done with the booty obtained, and how prisoners had to be treated. In this sense, it is worth remembering that some of the earliest definitions of jihād as war, of martial jihād, come from jurists.¹³ In his Kitāb al-jihād, al-Sulamī (d. 1106) quoted the following definition by al-Shāfiʿī (d. 820):

Therefore, the definition emphasized a fight for the defense and spread of the faith that leads to spiritual rewards. Finally, the fourth type of war in Ibn Khaldūn’s classification is the one undertaken by dynasties against those who try to emancipate from them and do not pledge obedience. Within this classification, Ibn Khaldūn describes the first two types as unjust wars and as revolt (baghī wa fitna), while the latter two as just wars (‘adl) and in defense of religion.¹⁵ In these lines, Ibn Khaldūn, according to the globalizing conception of history and ethnography of both the Muqaddima and the Kitāb al-‘Ibar, intends to consider all religions. It is clear, however, that he uses a discourse and a vocabulary (sharī‘a, jihād or fitna, for instance) which will soon be identified with Islam. In the following pages, I attempt to specify the reason why he uses such a vocabulary, and assess whether it is a purely ideological matter or one of language use and economy.

This kind of war typology, in which the concepts of justice and injustice are of great importance, is deeply rooted in Greek philosophy, and it was introduced into Islamic thought probably due to authors such as al-Fārābī (d. 950).¹⁶ Although the latter never refers to war as jihād, but always as ḥarb, he also explains the differences in terms of just or unjust confrontation. According to al-Fārābī, a just war is one carried out for the sake of the nation, to demand compensation for damage, to punish a nation for its acts, or to civilise other nations and help them to accept a better life, the latter being the category in which war for the spread of Islam would be included. Al-Fārābī explains it as follows: “to lead and force people to what is better and more excellent for themselves, when they are spontaneously unaware of it or are not willing to be led by anybody who knows it and invites them thereto by word of mouth.”¹⁷ This last statement, the resort to preaching, reminds us of one of the conditions of jihād: the legal necessity to invite infidels into Islam before initiating armed hostilities against them. A paradigmatic example of this condition in Islamic sources is the conversation between Rab‘ī b. ‘Āmir al-Tamīmī and Rostam, the Persian general, prior to the battle of al-Qādisiyya. Then the Muslim said

Undoubtedly, this discourse is expressed in the same terms as al-Fārābī’s category of just war, as he only speaks of showing the Persians the excellence, Islam.

Turning back to the philosopher, unjust wars are those undertaken only to humiliate, subjugate, and dominate, with no other purpose than that of being obeyed, to remedy wrath, or for the sole pleasure of victory.¹⁹ Even though he does not use the term jihād, he calls the warrior that carries out the just wars previously defined a mujāhid, thus clearly islamicising the meaning. Also, such a fighter is represented as a moral example of personal sacrifice for the sake of a nation. Moreover, in his description of the ideal governor, the capacity of leading jihād appears as one of his requisites.²⁰ 

Another author who explains armed conflict in philosophical terms is al-‘Āmirī (d. 992). According to him, there are three types of war: jihād, fitna, and banditry (taṣa‘luk). The first one is war carried out by rulers in order to preserve religion and social order; the second one is the one undertaken by nations due to their intolerance (ta‘asṣub); finally, the third one is aimed at looting and plundering. Whereas the first kind of confrontation derives from the faculty of reasoning, the other two proceed from irascible instincts.²¹ Like Ibn Khaldūn, these two authors try to build a universally valid typological framework for war. In my opinion, however, they do not quite succeed at it because of some of the notions they resort to, such as jihād or fitna, that have very deep connotations in Islamic thought.²² 

Continuing with the North African author, we see that religion even facilitates victory²³:

That is to say, with the establishment of religion and the cohesion it brings along, superiority and victory are attained.²⁵ 

For Ibn Khaldūn, religious indoctrination eliminates differences among the members of the group through the unification of their opinions: “The feeling becomes unanimous and desire becomes one. They are ready to die for it, whereas, despite they are weaker themselves, the nation they fight against have diverse aspirations, which is typical of falsehood, and tend not to support each other because fear of death dominates them.”²⁶ 

Our author exemplifies this idea with two historical cases: that of the battles of al-Qādisiyya and Yarmūk, during the early Islamic conquests, and that of the Almohad triumph. In the first example Ibn Khaldūn explains how, thanks to the religious cohesion and the impulse it brings, the Arabs of the first caliphate were capable of defeating much more numerous and better prepared armies.²⁷ Regarding the Almohads, the North African writer states that the religious preaching to follow the mahdī Ibn Tūmart received by the Maṣmūda (a Berber tribe) multiplied their cohesive strength, enabling their victory over tribes that, at first, were of a braver condition.²⁸ Therefore, religion is not only a justification discourse, but also becomes a social force that enhances ‘aṣabiyya, another key concept in Ibn Khaldūn, which is usually understood as the fundamental bond of a human group, the basic driving force of society and history.²⁹ This idea of cohesion and religion reminds us of the obsession of jurists and theoreticians to avoid civil war, fitna, and the chaos it brings along for the umma. Fitna is “disorder, riot, sedition.” It is a concept loaded with pejorative meanings, quite the opposite of the potential for social cohesion that religion has. But the fitna also derives from illegitimacy. This may be easily seen in Ibn Khaldūn’s war typology already commented on. Fitna is a mode of violence lacking in legitimacy and legality, as opposed to jihād, the just war that the fight for religion implies.³⁰ 

In sum, war for religion is not only just, but also, thanks to the cohesion and the impulse given by religious preaching, is more likely to obtain victory. One must also highlight the role that, in Ibn Khaldūn’s mind, charismatic figures play in this process. Prophets and saints are the ones who arouse the religious sentiment that enables cohesion and facilitates victory in battle, as in the case of the mahdī Ibn Tūmart, taken as an example by the North African writer. These are the figures that initiate wars of the third kind of the typology mentioned before, since they are the ones who preach the call of the divine law to war.

Let us now analyse how Ibn Khaldūn specifies such a bond between war and religion in Islam and in Christianity. According to the North African writer, in Islam jihād is a divine obligation that allows all men to embrace this religion either by consent or by force.³¹ In this sense, he follows the classical legal Islamic conception of the world, which is divided mainly into two areas: on the one hand, the abode of Islam (dār al-islām), where Muslims held political and religious supremacy; on the other hand, the abode of infidelity (dār al-kufr), where Islam had not yet extended and was therefore a territory susceptible of being attacked—thus becoming the dār al-ḥarb, the place of war —and conquered.³² In order to bring the spread of Islam through arms to completion, says Ibn Khaldūn, Muslims established a spiritual sovereignty and a temporal one subject to the former.³³ That is to say, he links the duty and capability to carry out war for religious expansion to the model of authority, to the relationship between spiritual and temporal authority. On the other hand, the North African writer claims that in the other religions, such as Christianity, not destined to the totality of men according to his opinion, people do not have the obligation to battle against the others, except in cases of legitimate defense.³⁴ This is why the temporal power is dissociated from the spiritual one: their members do not have the obligation to conquer other peoples in the name of religion, as is the case of the Muslim community, but they are simply urged to keep their religion within their own territory.³⁵ 

The final aim of expanding the dār al-islām around the world leads our author to articulate a political system and a theology of power for Islam according to which the spiritual and temporal authorities are intertwined. In the classical Islamic political thought of the caliphate and imamate, the caliph is the supreme temporal authority as well as the leader of the Muslim community, the umma, whose task it is to keep and regulate the Qur’anic prescriptions and doctrines, to apply and defend the sharī‘a, to lead the community prayer and expand faith. He is therefore forced to lead legitimate war, jihād, and to prevent illegal violence, the fitna.³⁶ 

Other earlier thinkers who also tried to present a universally valid perspective in their works, such as al-Mas‘ūdī (d. 956), had already emphasized the importance of the bond between the temporal authority and the spiritual one. The Iraqi author claimed that the relationship between power and religion was essential to maintaining the well-being of social order. To illustrate this relationship of necessity, he tells the story of a Chinese king who told his subjects that he had the intention of establishing a religion (diyāna) that would keep them together and regulate their lives, because without the law (sharī‘a) corruption would settle in the kingdom. Certainly when the bond between power and religion is broken, rebellion appears fitna.³⁷ Thus, we see how, despite his attempt to establish a theory with universal validity, al-Mas‘ūdī islamicises his arguments through the terminology he uses, just like Ibn Khaldūn.

But let us turn back to our author and focus on the case of Christianity. Ibn Khaldūn affirms that spiritual power, dissociated from the temporal, lies in the hands of the so-called patriarch. He is the head of this religion, is in charge of its prescriptions, is also the successor of the Messiah, khalīfat al-masīḥ—an idea that is close, even identical, to the idea of the pope at Rome as the Vicar of Christ—and is the one who sends his representatives and delegates to the most remote regions under Christian control.³⁸ After the schism of Christianity, each region chose a patriarch, the one at Rome later called the pope.³⁹ He also describes him as a follower of the Melkite ritual, something that shows that for Ibn Khaldūn the doctrinal division between the Eastern and the Western churches never took place. Interestingly, this also exemplifies that the very term Melkite was stripped of its original meaning to prove the union between spiritual and temporal power at Constantinople.⁴⁰ 

Among the Islamic authors, the figure of the pope was gaining importance during these centuries, especially after the Gregorian Reform initiated by Pope Gregory VII (d. 1085) and the Latin expansion that began in the 11^th century.⁴¹ Until that time, authors like Ibn Rustah (d. 913) had described him as the local king of the city of Rome. Already in the 13^th century, Yāqūt (d. 1229) and Ibn Wāṣil (d. 1298) defined the pope as a religious leader whose authority widely exceeded the frontiers of the pontifical city. And later on, the Egyptian al-Qalqashandī (d. 1418), Ibn Khaldūn’s contemporary, compared him to the caliph, describing him as he who enthrones the kings of Christianity.⁴² 

As for the political role played by the pope, Ibn Khaldūn seems to believe that it is minimal when he claims that Rome belongs to the Franks and that it is their king who controls this region.⁴³ Therefore, it seems that the Franks would occupy the temporal power, whereas the spiritual one, dissociated from the former, would be in charge of the pope. Undoubtedly, the crusader period seems to have reinforced, in the view of Muslim authors, the notion of European unity under the appellative of Franks, something that can already be observed in previous authors such as al-Mas‘ūdī. Descriptions of the rise of a strong Frankish power as a successor of the Roman or the Byzantine Empire, which we see in works like those of Ibn al-Athīr (d. 1233), may actually respond to the necessity of explaining European expansionism.⁴⁴ 

However, the temporal and the spiritual do not always appear wholly unconnected. Even al-Mas‘ūdī claims that all Frankish peoples, including Galicians, Germans, Bulgarians, and Slavs, acknowledge the authority of Rome, which since then has been their capital.⁴⁵ Likewise, Ibn Khaldūn establishes some kind of connection between both powers by means of the figure of the emperor. The Maghrebi author claims that it was the norm for the pope to encourage Christians to accept the power of a king and to submit to him, despite their likes and dislikes, in order to prevent disunity, an idea that reminds us again of the Islamic obsession of preventing fitna. This king, continues Ibn Khaldūn, they call emperor, and it is the pope himself who personally places the crown on his head to beg for blessing upon him.⁴⁶ We see how the spiritual power is not only bound to the temporal, but it also legitimates and blesses it, and religion remains the reason for cohesion.

With these last images it is apparent that Ibn Khaldūn is coming closer to an understanding of the pontifical institution by comparing it to Islamic categories such as the caliphate itself. The emperor, the “crowned one” (al-mutawwaj) as termed by Ibn Khaldūn in an attempt to give a meaning to this term, obtains unity from the ‘aṣabiyya obtained in turn by the pope and his religious authority.⁴⁷ In addition, it is likely that the pope, the khalīfat al-masīḥ, was conceptualised sometimes as a figure analogous to that of the caliph, namely as the title bearer of political and religious authority. Yāqūt, for instance, claimed that the Franks considered the pope the nā’ib al-masīḥ, the representative of the Messiah, and compared him to the amīr al-mu’minīn, the “commander of the believers” of the Muslims, a term interchangeable with that of caliph and which included both kinds of authority.⁴⁸ 

In sum, as opposed to the Islamic case, where, according to Ibn Khaldūn, the jihād is mandatory in order to achieve the spread of Islam all around the world and to facilitate the subordination of the temporal power to the spiritual one. Within Christianity, war for religious expansion is not possible, as there is no room for legitimacy or for justification of the war act through religion because of the dissociation between the spiritual and the temporal power. However, as we have seen, the Maghrebi author does describe some kind of relation between the pontificate and the empire.

Ibn Khaldūn is, therefore, establishing in his Muqaddima three main elements that underlie the connection between war and religion: cohesion bestowed by religion, increasing the capacity of victory; the duty of spreading religion by force; and the possibility and capability of carrying out such an expansion through the mechanism of authority—that is, of the relation between the spiritual and the temporal power. These are the characteristics that determine that a war is religious; a type of confrontation that the Maghrebi author calls jihād and that is, according to him, possible and—more important—mandatory due to divine law in Islam but not in Christianity.⁴⁹ This is to say, a war carried out for the defense of God and the spread of His religion, sanctioned by it and, consequently, holy. In this sense of war—which we will understand as holy war— we now look for transcultural functionality.

After analysing how Ibn Khaldūn conceptualises and theorises on war and its relation with religion as a means of expansion of faith, let us now see, following the Kitāb al-‘Ibar, how he describes and tells several episodes known to be conceived of as holy war by Christians, as the defense and spread of faith through arms. We will explore if any of those three elements that connected war with religion and that determined whether a war was religious or not are visible in his narration of the wars led by Christians.

Specifically, due to the length of the Kitāb al-‘Ibar, we will focus on three events. The first of them is the crusader conquest of Jerusalem, selected because of its historical and symbolic importance in the course of the Christian holy war.⁵⁰ The second episode is the battle of Rio Salado, chosen due to its direct relationship with Ibn Khaldūn both in its geographic and chronological aspects. And, in addition, it was also classified as a crusade. The third event is Louis IX’s expedition to Tunis, selected because of its consideration as a crusade, its contextual relationship with Ibn Khaldūn, and because, as we will see, the way in which this episode is narrated by the Maghrebi author challenges his conceptual framework about war for religion.

Ibn Khaldūn, in two sections of his long book, tells in detail the story of the conquest of Jerusalem during the First Crusade, one he dedicates to the Seljuks and the other dealing with the Fatimids.⁵¹ The North African writer begins his story by referring to the fact that the front of expansion of the Franks did not only extend along Holy Land, but also along other regions of the Mediterranean, like Sicily.⁵² He mentions as well how the crusaders received help from the Byzantine emperor to cross the Strait of the Bosphorus and how, after going through Acre, they besieged the city of Jerusalem for 40 days until they managed to break in through the northern part, looting (violating, desecrating) the city for an entire week.⁵³ Its inhabitants sought protection in David’s miḥrāb—possibly the citadel—and remained there three days, until the conquerors offered them safeguard up to Ascalon. In the [plain of the] mosque, continues Ibn Khaldūn, they murdered 70,000 citizens or more, among which were scholars, ascetics, and pious peoples, and they took uncountable riches by force. The clamour for help, Ibn Khaldūn tells us, even reached Baghdad, where the caliph ordered the sultan Barkiyārūq to carry out the jihād to regain Jerusalem, but his differences with his brothers—described by the Maghrebi writer as fitna, as unjust war according to his theoretical typology—prevented him from doing it.⁵⁴ Thus, their lack of cohesion bought them their defeat. On the contrary, the united Franks gave the government, says Ibn Khaldūn, to Godfrey from among their kings.

Ibn Khaldūn follows here very closely the same story that recent researchers have termed the “Islamic narrative” of the conquest of Jerusalem and made popular by Ibn al-Athīr.⁵⁵ This consists of three main elements: the great massacre of 70,000 Muslims, the sacking of al-Aqṣā and of the Dome of the Rock, and the request for help to Baghdad. Like Ibn al-Athīr and al-Sulamī, who wrote a forerunner to this story, Ibn Khaldūn, as already seen, refers to a Frankish front of Mediterranean amplitude and to crusader cohesion as opposed to the disunity of the Muslims as one of the causes of their defeat.⁵⁶ Al-Sulamī and Ibn al-Athīr also presented the crusader campaign as jihād, yet, in the case of Ibn al-Athīr, as a jihād somehow delegitimised by looting.⁵⁷ Ergo, they describe the Christian offensive as a war of religious expansion, as did an anonymous poet later quoted by the historian Ibn Taghrī Birdī (d. 1470). That poet speaks of the Frankish campaign as an attempt to spread an impure form of Christianity by force;⁵⁸ or Saladin in some letters transmitted by Abū Shāma, who would not have spoken of jihād, but rather of ijtihād, of the effort and sacrifice of the Franks to defend their religion.⁵⁹ 

However, far from presenting the crusader campaign as a war of religious expansion, Ibn Khaldūn describes it as an impious war, an episode in which a holy city was desecrated and violated. In this sense, he uses the verb istibāḥ in speaking of the crusader actions after their entry into the city, which does not only denote “sacking,” but also “desecrating, sullying honor.” Other previous authors did not describe this episode as a war of religion either: al-‘Aẓīmī claims it was a campaign in revenge of the impediment allegedly imposed on the Christian pilgrims to visit Jerusalem, while Usāma b. Munqidh believed that the only objective of the crusaders was to increase their wealth.⁶⁰ 

In the Battle of Rio Salado in October 1340, Castilian and Portuguese forces confronted a Marinid-Nasrid coalition in the context of the Strait of Gibraltar war. Pope Benedict XII became remarkably involved in it by providing the battle on March 7, 1340 with the Exaltamus in te. In this papal bull, he raised the event to the category of crusade and gave the participants numerous spiritual and economic benefits.⁶¹ The Vatican archives preserve more than 100 documents directly and indirectly related to the Battle of Rio Salado. This is good proof of the great interest and support displayed in the fight against the Marinids by the pontiff, who was moved by “the victory against the enemies of the Catholic faith.” The pontiff presents the war laid as saving, freeing and defending the Church while extending the cult of Christ in the occupied territories.⁶² He also took the required steps for the Iberian Christian Kingdoms to reach peace, and thus made possible a great alliance against the infidel. Benedict took part in the various disputes that Castile had with the Navarrans and Aragonese and, especially, with the Portuguese. He also addressed the city of Genoa to send galleys to Castile and to withdraw Genoese support from the Marinids. However, the Genovese fleet arrived late to the battle.⁶³ 

Ibn Khaldūn points out that the Castilian king met the Christian nations (umam al-naṣrāniyya) before the battle, especially the lord (sāḥib) of Lisbon and of Gharb (west) al-Andalus. However, he says nothing of the pope’s intervention or of a possible religious motivation for the campaign, and the vocabulary he uses to speak of the Christian advance and attack does not evoke religious war either.⁶⁴ Moreover, the fact that he repeatedly calls the Castilian king a “tyrant,” despite being a common term used in the Islamic chronicles to refer to Christian kings, signals a high degree of illegitimacy. A tyrant is one who oversteps the limits of justice, an oppressor, and a rebel. The term (ṭāghiya) derives from a root occurring frequently in the Qur’an with a connotation of insolence and arrogance, of contempt of the law of God and hostility towards the apostles of God. It implies, therefore, an excess of infidelity.⁶⁵ It is always a negative religious-political term, describing somebody who does not have Islamic legitimacy in the exercise of power, somebody who governs without the Islamic law. As already mentioned, it has the semantic image of overflowing, something that is not surprising if we take into account that the term occurring in the Qur’an to refer to laws created by God is ḥudūd, “borders, limits.”⁶⁶ In the Andalusi chronicles, the term ends up being a synonym of “Christian king,” while yet used to designate those Muslims that rebel against the established Islamic power.⁶⁷ Thus, in principle, a tyrant could never conduct just, and therefore holy, war.

Conversely, Ibn Khaldūn always qualifies Marinid actions as jihad.⁶⁸ He says that the sultan Abū al-Ḥasan was convinced that, despite their defeats, God would finally reward them with victory, invoking the verse Q. 61:8: “They want to extinguish the light of God with their mouths, but God will perfect His light, although the disbelievers dislike it.”⁶⁹ Naming the Marinid acts as jihād is in line with the description of al-Andalus made by the North African writer in a brief summary of Andalusi history placed at the beginning of the section on the Marinids, explained in terms of constant conflict between Christians and Muslims.⁷⁰ The land of al-Andalus is represented as a frontier (thaghr li-l-muslimīn), a place of jihād, of ribāṭ, and of martyrdom and happiness for the Muslims (madārij shahādati-him wa sabīl sa‘ādati-him), likened to a constant blaze, where the faithful stood between the claws and the jaws of the lions of infidelity. Ibn Khaldūn is following a tradition that was already settled—and widespread, especially after the 13^th century, due to the Christian advance—originating in certain hadiths of the Prophet, in which al-Andalus is described as the last land to which the Muslim religion will propagate and also as the first one from which it will disappear. These texts reflect the “feeling of precariousness” of Muslim presence in the Iberian Peninsula, the idea that such a domain is doomed to end sooner or later due to prowling dangers, chiefly those represented by the Christians. Hence, al-Andalus also remained in the Muslim imagination, as we have seen in Ibn Khaldūn’s text, shaped since the earliest times as a land of ribāṭ, namely as a place of congregation of pious peoples that combine prayer and other religious acts with the fight against the infidels.⁷¹ 

After analysing these two examples, it seems that the historiographical practice begun by Ibn Khaldūn in his Kitāb al-‘Ibar—how he actually narrates the facts—is in agreement with his theory—his a priori cultural and ethnographical vision of Christianity—on the bond between war and religion in Christianity formerly presented by the North African writer in his introduction, the Muqaddima, as pointed out by most authors.⁷² That is to say, there existed in the Christian world no religious justification for the spread through arms, and there was no room for the war for religion, for holy war as Ibn Khaldūn viewed it. But if we pay attention to other passages of this long work, does this conclusion still stand? We find out immediately that it does not. Throughout his work we find evidence that Ibn Khaldūn perhaps did conceive, at least indirectly, the Jerusalem and the Battle of Rio Salado episodes as campaigns of religious expansion, as religious wars.

According to the section of the Muqaddima in which the Tunisian author describes the naval power, after the demise of the Fatimid and Umayyad dynasties, the Christians opened a battlefront. That reminds us of the one already mentioned in the “Islamic narrative” popularised by Ibn al-Athīr—against islands like Sicily, Crete, and Malta. This later took them to press on to the Syrian coasts and seize Tripoli, Ascalon, Tyre, and Acre, taking over all of the strategic points, and finally to enter Jerusalem and built a church inside as a manifestation of their religion and faith.⁷³ That is to say, Ibn Khaldūn leads the reader through a discourse that seemingly points out that the final goal of the campaign was the conquest of Jerusalem and the establishment of Christian religion there by means of the construction of a church. Such an idea is confirmed by another passage very similar to that of the Muqaddima, where it is also specified that the church, which they revered with great devotion and were very proud of, had been erected upon the Holy Rock, the mosque of al-Aqṣā according to another passage of the Kitāb al-‘Ibar summarising the history of the Franks.⁷⁴ 

Such an ecclesiastical construction represented, therefore, the triumph of Christianity over Islam, and its well-chosen location seemed to confirm it. The descriptions of the reconstructive efforts of Saladin point towards a similar strategy. According to Ibn Khaldūn, when he had regained the city after the Battle of Hattin, the sultan proceeded to demolish the church and rebuild the mosque, purifying al-Aqṣā (ṭahhara al-masjid al-Aqṣā) of the false doctrines of the infidels.⁷⁵ The purifying element in war actions against Christians is always present in Islamic chronicles, thus stressing the religious character of those campaigns. Without a doubt, church buildings themselves played an important role in such cleansing works. A clear example of this discourse of conquest and purification may be seen in the chronicles relating the Almohad campaigns, in which the seizing of a town is always succeeded by the transformation of its church into a mosque or by its demolition.⁷⁶ It is also interesting to observe how al-Sulamī chose for the reading of his Kitāb al-Jihād a mosque in Bayt Lihya, near Damascus, built upon an older Christian church.⁷⁷ 

This procedure was also usual among Christians, who transformed mosques into churches. Mosques were viewed as symbols of Islam and the effective conquest of a town was usually signaled by placing a banner in the minaret of the central mosque, as in Seville after Ferdinand III’s conquest of the city.⁷⁸ In Cordoba, besides the banner, a cross was also exhibited. Thereafter, the monarch took part in a victory parade that ended up with a mass in the recently converted church, as in Cordova (1236), Jaén (1246), Seville (1248), and Murcia (1266).⁷⁹ Hence, the conquest-purification-conversion narrative used by Ibn Khaldūn to describe the crusader conquest of Jerusalem suggests that although Ibn Khaldun, as we have seen, saw this action as impious, he did understand it as a war for the spread of religion and apparently comprehended de facto the religious component of this Christian campaign. Although this type of speech is a topos that aims to show the contamination caused by the infidels, it does highlight that the purpose of the enemy’s campaign is the expansion of their religion, of infidelity.

In the context of the Battle of Rio Salado, this kind of evidence for wars for the spread of Christian religion is difficult to find, although it is easier if we enlarge our focus to the entire Strait of Gibraltar war. A few verses of a poem, quoted by Ibn Khaldūn and allegedly recited by the secretary of the Nasrid sultan Muḥammad II to the Marinid sultan Abū Yūsuf Ya‘qūb in the year 1275-1276, seem to request the help of the Marinids against the Christian advance. The underlying idea is that the Christian campaigns had as a first consequence the spread of that religion at the expense of Islam, and that such a religious zeal turned into a form of cohesion that made coreligionists, brethren of religion, help one another. The Muslims, on the contrary, had lost this virtue of solidarity.

Moreover, according to Ibn Khaldūn, for the Christian kings anything that did not lead to the continuation of the war against the Muslims was humiliating for their religion: allegedly, Sancho IV had sent envoys to negotiate peace with the Muslims despite it being “humiliating, dishonest and unjust for his religion (al-khasf wa al-haḍīma li-dīni-hi).”⁸¹ It seems therefore that Christianity needed that confrontation, which became, as in the Islamic case, a divine duty.

However, without a doubt, the story that most clearly indicates that our author perhaps did conceive of the possibility of a spread of Christianity through arms in similar terms to that of jihād and, therefore, that his concept of holy war could be transcultural, is the third of the episodes that have been selected as case studies. Following the summary of the history of the Franks mentioned earlier in relation to the conquest of Jerusalem and its reconquest by Saladin, Ibn Khaldūn focuses on the Eighth Crusade. This expedition was the second one by Louis IX of France and the campaign by which he tried to conquer Tunis. Supposedly, he wanted to establish an operating base there from which he could attack Egypt and the Holy Land, as suggested by the North African author:⁸² 

Many points in this fragment are worth analysing in detail. Just as in the episode of Rio Salado, here is an example of union between Christian kings to fight against the Muslims. However, as opposed to the Iberian case, here the pope comes directly into play by seeking, encouraging, and obtaining such an alliance, and even the benefits given by the pope for taking part in the campaign are detailed, something quite unusual in the Islamic chronicles. Therefore, it seems that the absence of a bond between spiritual and temporal power, which in the Muqaddima justified the non-existence of Christian holy war, is proven false here. But, above all, the term used by Ibn Khaldūn to refer to this campaign is worth noting: ghazwa. A few lines earlier the North African writer had used this word along with that of jihād to describe the campaign of Saladin to regain Jerusalem, a combination our author resorts to on more than one occasion.⁸⁴ In fact, when Ibn Khaldūn uses this term, he always does so to refer to the conquests of Christian territories by Muslims, often in a usage similar to, or a substitution of, jihād.⁸⁵ He also employs it to refer to the Islamic conquest of al-Andalus as a synonym of fatḥ, a term that, as proven by Alejandro García Sanjuán, has clear religious connotations of war sacralisation in one of its multiple meanings.⁸⁶ This is already so in the Qur’an itself: chapter 48, narrating, according to the exegetes, the conquest of Mecca by the Prophet after the al-Ḥudaybiyya pact, is called Sūrat al-Fatḥ. This means that the most important Muslim victory in the time of the Prophet, the regaining of the most sacred city, belongs to that category.

Even though this term ghazwa originally meant nothing more than a hostile raid, in the course of time it acquired a religious meaning and, above all, designated attacks against non-believers.⁸⁷ We must not forget either that the campaigns carried out by the Prophet were named maghāzī, a word derived from the same root. In fact, the only time a derivative appears in the Qur’an is in verse 3:156, criticising those who disown the fighters (ghuzāt) who leave on a raid in the path of God and die in it. This verse clearly refers to holy war, to the path of Allāh.⁸⁸ Therefore, the term ghāzī was reserved to those who took part in a ghazwa, understood as a raid against the infidel. The Turkish poet Aḥmedī, a contemporary of Ibn Khaldūn, gave the following definition of ghāzī:

In the Islamic West, one can detect a similar evolution. Already in the early 11^th century, the term was applied to designate all soldiers native to North Africa, and more specifically to the western Maghreb, who arrived in the Iberian Peninsula to make the jihād.⁹⁰ In addition, however, within the Marinid and Nasrid context in which Ibn Khaldūn developed part of his activity, there existed a military body, the shuyūkh al-ghuzāt al-mujāhidīn, “sheikhs of the jihād fighters,” that strengthened the link between this root and holy war. This implied the arrival into al-Andalus of Maghrebi soldiers,ghuzā, who came to increase the ranks of the Nasrid army. Having authority over them, there arrived a member, usually a dissident, of the Marinid royal family—a descendant of the emir ‘Abd al-Ḥaqq Ibn Maḥyū, founder of the dynasty, according to Marinid chroniclers—who was considered a shaykh al-ghuzāt.⁹¹ This way the sultans of Fez delegated their obligation to intervene on the other side of the Strait of Gibraltar to elements of which affinity with the dynasty was purely nominal, and, simultaneously, they reduced tensions and potential riots in their own territory.⁹² Apparently, this institution has its origin in the period of the Marinid sultan Abū Ya‘qūb Yūsuf (d. 1307), under whose regime the Marinids experienced a period of weakness in al-Andalus and in the Maghreb. This could fit perfectly with the creation of the shiyākha, since the attraction and employment of dissident and rebellious elements could actually become an efficient Nasrid political instrument against the rival North African dynasty.⁹³ Despite this Granadan interest, what stands out is the special autonomy and political independence acquired by this institution inside the Nasrid monarchy, not to mention tax and economic benefits. In theory, the Nasrid sovereign had absolute authority over his army, but in practice, the shaykh al-ghuzāt mobilized his troops, something that gave the latter a high degree of power with which he could put pressure on the sultan in favor of his own interests.⁹⁴ Their hypothetical function and their relation to holy war interests us most at this point. Ibn Khaldūn himself describes them as those in charge of making the jihād along with the Nasrids of Ibn al-Aḥmar, and affirms that al-Andalus “would have known weak conditions, had it not been for the divine inspiration of these zanāta to make the jihad.”⁹⁵ 

Therefore, the fact that our historian uses the term ghazwa to refer to Saint Louis’ Tunisian crusade is still meaningful, all the more so if we take into account the commentaries he himself makes, as we have seen, regarding the pope’s intervention: the pope asked the Christian kings to support the French monarch and even gave them economic benefits. He no doubt conceived of this campaign as a war for religion, using, as we have seen, specific holy war terminology—which he only uses to refer to expeditions carried out by Muslims against infidels—with clear implications in the Islamic world. The fact that it is so explicitly characterised as a war of religious expansion, whereas in previous campaigns it is made more subtly, may have to do with his relation with the Hafsids. This dynasty, a victim of the Eighth Crusade, always remained very close to the Banū Khaldūn.⁹⁶ Moreover, the North African writer could have better access to sources and witnesses of this episode in Tunis and, above all, this initiative had a greater repercussion in the Mediterranean, if compared, for instance, to the Battle of Rio Salado. We must not forget that the propaganda campaign for this crusade was very active, despite the fact that only the eldest son of the English king took the cross together with the Capetos, or that Louis IX’s reputation as terribly pious and devout probably added sacrality to the campaign in the eyes of many of his contemporaries.⁹⁷ A few days after his death in Tunis, the body of the French king was already working miracles, and 27 years later he was canonised, finally appearing in the Kitāb al-‘Ibar, as we have seen, as Saint Louis.⁹⁸ 

The rest of the narrative does not give us many clues about whether Ibn Khaldūn thought that Louis IX and his martial actions had a greater religious component or were better suited to the category of holy war. However, it does show that the Maghrebi author held Louis IX in greater consideration than the rest of the Christian leaders, since he repeatedly called him “sultan,” something that is not usual in the work of the North African historian when referring to an infidel ruler, usually called malik (king) or amīr (prince).⁹⁹ In fact, in this same passage he calls the king of Aragon “malik Barcelona.” The term “sultan,” which appears in the Qur’an 37 times, literally means “authority.”¹⁰⁰ In its Qur’anic use, it usually seen as granted by God. While the title of malik had a pejorative connotation, that of “sultan,” since the change in its use by the Seljuks, constituted a usurpation not only of the title but also of the substance of caliphal political authority: the caliph was limited, therefore, to spiritual authority.¹⁰¹ Was Ibn Khaldūn, by calling Louis IX a “sultan,” describing the relationship established by the French king with the pope for the passage of his expedition to Tunis? Louis would exercise political authority while the pope, called khalīfat al-masīḥ in the passage, would be in charge of the spiritual one. The parallelism between caliph and pope proposed by Yāqūt would make sense here. Nevertheless, as we have seen, the role played by the pontiff in that campaign, according to Ibn Khaldūn, was very active, which made it possible for both authorities (political and spiritual) to go hand in hand and granted to this episode, characterized as ghazwa, an indisputably religious nature.

After this analysis of Ibn Khaldūn’s work, there is an evident difference between Ibn Khaldūn’s “historiographical theory” in the Muqaddima, where he develops his conceptualisation of holy war as an absolute notion, and his “historiographical praxis”—how he actually describes historical events. We can draw several conclusions in an attempt to explain this apparent incoherence.

The Maghrebi writer established in his Muqaddima, as we have seen, three main elements underlying the connection between war and religion: cohesion bestowed by religion, increasing the capacity of victory; the duty of spreading religion by force; and the possibility and capability of carrying out such an expansion through the mechanism of authority—that is, the relation between the spiritual and the temporal power.

The first element is found in the examples we have collected. In the Holy Land, the crusaders’ cohesion allowed their victory over the Muslims, who were unable to carry out the jihād because they were in a state of fitna; in the battle of Rio Salado and in the Eighth Crusade, Ibn Khaldūn tells us of the union of the Christian kings; and, in addition, the poem of the Nasrid secretary praises the help that the Christians brought to their brothers of religion. Despite the opinion expressed by the Maghrebi author in his introduction, the second element also occurs in the selected fragments. He represents the building of a church in the Ḥaram al-Sharīf, and the consequent spread of Christianity, as the goal of the conquest of Jerusalem, something that filled the crusaders with pride and devotion. It was the objective of the entire Mediterranean front of the Franks. But, in addition, to avoid confrontation with the Muslims was understood by the Christians, according to Ibn Khaldūn’s episode on Sancho IV, as a source of humiliation for Christianity: in other words, Christian religion recommended, and approved, war against the infidel. Lastly, the close link between spiritual and temporal power, which would facilitate such a religious spread through arms, may not only be sensed in his description of the relationship between the pope and the emperor in the Muqaddima, but also in the pontiff’s intervention in favor of Louis IX’s plans in the narrative of the Eighth Crusade. Moreover, there appears an additional element to which Ibn Khaldūn gave importance when he linked war with religion in the Muqaddima: that of charismatic figures. Let us not forget that they—prophets or saints, as the North African writer said—were the ones who infused people with the religious sentiment necessary to attain cohesion and, consequently, victory. In this sense, such religious leadership, such charismatic domination, is the one exercised by the pope in the episode of the Eighth Crusade, who is described, it must be reminded, as the successor of the Messiah (khalīfat al-masīḥ), and Louis IX, already characterised as a saint in the Kitāb al-‘Ibar.

Therefore, after analysing these elements throughout the Kitāb al-‘Ibar, we may conclude that Ibn Khaldūn did actually consider, even within his own conceptual limits, the possibility, duty (for Christians), and existence of a Christian holy war, and of a religious discourse of justification for the expansion of Christianity through arms. The concept of holy war our author had previously developed in the Muqaddima as unique to Islam through specific elements (cohesion bestowed by religion capable of increasing the chances of victory, the obligation of armed proselytism, and the need of a link between religious and political authority) becomes transcultural in the narrative of the events in the Kitāb al-‘Ibar, as it is also applied to Christianity, even though terms like ghazwa, that, throughout his entire work, appear to be reserved only to Islamic holy war.

Thus, in his “historiographic theory” Ibn Khaldūn, as other authors such as al-Mas‘ūdī and al-Fārābī had done, islamicised through terms (sharī‘a, jihād, fitna) and through arguments a conceptual framework and a set of categories that were intended to be universal, but ended up becoming plausible only in their application to the Islamic reality. Quite the opposite happened, however, in his “historiographical praxis.” The employment of “Islamic” concepts (like ghazwa) led him to apply such a conceptual framework, which had been theorised as unique to Islam, to Christian experiences, thus somehow acknowledging an idea of holy war that surpassed religious barriers, becoming transcultural. It would be interesting to analyse if the Christian conceptualisation of holy war also crossed frontiers and was applied to Islamic realities. Given the nature of this article, here we can only recall the case of the anonymous Christian author who, on the siege of Acre carried out by Saladin, ascribed religious motivations to Muslim warriors. He claimed that the caliph of Baghdad had promised remission of all sins to those Muslims who joined the campaign.¹⁰² No doubt, he was transferring to the “caliphal world” a pontifical prerogative.

Turning back to Ibn Khaldūn and to the conclusions, what is the reason for such a tension between the conceptual and theoretical framework he developed in his introduction, which only conceives (Islamic) jihād as a holy and therefore just war, and his historiographical genre, in which he narrates and explains several Christian military campaigns within the limits he had drawn for the jihād and defines them as holy? Despite its singularity and personality, which endows it, as acknowledged, with its own entity, one cannot forget that the Muqaddima is still the introduction to Ibn Khaldūn’s historical work. The differences we find between it and the remainder of the Kitāb al-‘Ibar respond to the difficulties that the historian, then and now, is confronted with when trying to adjust his historiographical narrative to the theoretical framework that he has previously sketched out.

We could seek an answer to the question that concerns us in a decision of linguistic pragmatism. The selection of images and terminology typical of holy war in the description of certain Christian campaigns could respond to an attempt to be understood by his audience—Arabic, Islamic, and those familiar with such language—and not to highlight the religious aspect of those military actions. However, it is highly unlikely, since on most other occasions he uses neutral terms in the religious sphere—such as ḥarb—to describe wars conducted by Christians, which are perfectly understandable to his readers. Hence, in these cases Ibn Khaldūn consciously stresses the religious element in those campaigns, thus sacralising them. The breach and the tension that exists between his theory and his historiographical praxis must then be explained in different terms, ideological in our view.

To admit the existence of a Christian holy war meant that the war carried out by the infidels against the Muslims and the religious expansion they could obtain at the expense of Islam was a just war. That is why Ibn Khaldūn, who nevertheless ended up admitting this fact later in the course of his historiographic work, denied such a possibility in his theorisation. In theory, the war typology of armed proselytism was a privilege unique to Islam and to its status of perfect religion, something that, according to Ibn Khaldūn, the founders of Christianity themselves, the apostles, had rejected, as they instead tried to evangelise exclusively through words.¹⁰³ Something similar was argued by Ibn Taymiyya in the letter he sent sometime between April 1303 and May 1304 to a Cypriot crusader. In it he requests the release of the Muslim prisoners, captured, with all likelihood, in some of the crusader raids upon the coasts of the Eastern Levant during the Syrian campaigns of the Ilkhanid Ghāzān Khān in 1299, 1300, and 1303.¹⁰⁴ The letter, accompanied by a long exposition of history of religions in an attempt to convince his interlocutor of the supremacy of Islam, claimed that Jesus and the apostles had opposed armed proselytism, and that, therefore, there existed in Christianity no such possibility, whereas that had been actually ordered by God to the Muslims through the Prophet.¹⁰⁵ In other words, it did exist in Islam such a model of just and licit war that Ibn Khaldūn had classified in the Muqaddima, as there was a call of the divine law to holy war after Muḥammad’s revelation, whereas in Christianity such a reality, such a legitimation of violence, could not exist on account of Jesus’s opposition to it.¹⁰⁶