Holy War and the Kingdom of Heaven: Pope Leo IV’s Letter to the Frankish Army (847/8?)

I’ve recently had cause to think about holy war in the Carolingian period again. One of the things that struck me is that this is a subject that suffers from being in the shadow of the Crusades. This is not just because the Crusades are the archetype for medieval Christian holy wars, by which all others are measured and understood. Much of the scholarship on holy war in the Carolingian age has been carried out by Crusades specialists trying to understand how a religion of peace whose earliest practitioners were suspicious of military affairs came to be the faith of people crying out ‘Deus le volt’ as they stormed Antioch and Jerusalem in the last years of the eleventh century. The result tends to be a whistlestop tour across a millennium, hitting a couple of perennial points such as Constantine’s conversion and Augustine’s formulation of just warfare, before racing onto the next stop a couple of centuries later.

One of the old chestnuts briefly paused at is the letter of Pope Leo IV (r.847-853) to a Frankish army in the middle of the ninth century. This letter is important as possibly the first place a Christian religious authority explicitly says that soldiers who die fighting a holy war automatically go to heaven. This is of great significance for historians of the Crusades, because the concept of a papal indulgence for those who participated in the campaign is at the heart of many definitions of a Crusade. But in most scholarly accounts the letter merits half a sentence and a footnote. This is a shame, because it’s a fascinating text. Because of this neglect, and because if people on the internet are going to argue about medieval holy war they should at least have access to decent sources and I don’t think the Fordham translation is particularly good, I thought it might be useful to offer one of my own.

Leo IV, Epistolae selectae, ed. A. Hirsch-Gereuth, MGH Epp 5 (Berlin, 1899), no. 28, 601.

To the army of the Franks

1. Put aside all fear and panic, and endeavour to act manfully against the enemies of the holy faith and the foes of all lands.

2. Likewise. Up until now your forebears have always proved to be victorious when they marched forth in military array, and no multitude of people could overcome them. For we have not heard that they ever returned without the fame of a victory.

3. Likewise. Beloved, we want all of you to know that whoever dies faithfully in this contest of war (which we say not wishing it comes to pass) will by no means be denied the kingdom of heaven. For the Almighty knows that if any of you die, he died for the truth of the faith and the salvation of the soul and the defence of the country of Christians, and therefore he will obtain the aforesaid prize [i.e. heaven] from Him.

An important thing to note about this letter is that it only survives in later legal collections. The full text is preserved in a manuscript known as the Collectio Britannica (BL Add MS 8873 f.167v) which contains a collection of canons probably assembled in France in 1108. The canonist Ivo of Chartres (d. 1114) included it in his Decretum (X.87) and in slightly shortened form in his Panormia (VIII.30). An abbreviated version of Leo’s letter, attributing it to the more celebrated Pope Nicholas I (r. 858-867) makes an appearance in Gratian’s Decretum (C. 23 q. 8 c. 9). The letter survived because it was used as a legal precedent, but this means we don’t have any sense of context for when it was written, who exactly Leo was addressing or how it circulated before the late-eleventh century (i.e. when the Crusades began), although the Collectio claims to be drawing the letters from Leo’s Papal Register. The conventional date of 853 assigned to the letter has no particular evidence behind it and is not to be trusted, particularly as there was no Frankish army near Rome in that year.

We can say a little more about the context of Leo’s pontificate. It was defined by an event that took place the year before he was elected, when in August 846 a Saracen raiding party sacked the part of Rome that lay outside the Aurelian walls, including the basilicas of Old St Peter’s and San Paolo fuori le Mura. As Pope, Leo responded to this disaster by repairing the basilicas, fixing the city walls and establishing a new set of fortifications, known as the Leonine Walls, which contain what is now the Vatican City. Knowing that the raiders might return, he also sought to mobilise aid from the Carolingian rulers of Italy, Emperor Lothar I (r. 817-855) and his son Louis II (r. 844-875), and from southern Italian cities such as Naples, Gaeta and Amalfi. This preparation paid off when a Christian naval coalition intercepted and defeated a Saracen fleet heading towards Rome at the Battle of Ostia in 849. Despite this success, the sack of 846 was an immensely traumatic moment, which sent shockwaves across Christian Europe and threw Rome into a state of emergency. Although we know that the Eternal City would remain safe from the Saracens from then on, Leo obviously didn’t. In 847 Saracen pirates took over Bari, establishing an Emirate that would raid into southern Italy for the next two-and-a-half decades. This atmosphere of crisis helps to explain the unusual contents of the letter.

Raphael’s depiction of The Battle of Ostia in the Apostolic Palace in the Vatican, painted in 1514-15. Note Leo IV on the left, bearing a strong resemblance to Pope Leo X (r.1513-1521).

Although Leo specifies that the Frankish army is fighting against enemies of the faith in c.1, the discussion of holy war is mostly confined to c.3, where it is pretty explicit. Franks who die righteously in this war will go to heaven. Leo lays stress on the causes they are defending – the truth of the faith, their souls, and the defence of Christendom. It’s hard to find much in the way of precedent for this statement. This is surprising given how many of the elements that made it were already available. Paul compared Christians to soldiers fighting for the cause. Christian martyrs had been dying for the faith from the very beginning, and they automatically won eternal life for doing so. As I have discussed elsewhere, Charlemagne waged wars that were meant to bring Christianity to new peoples such as the Saxons, or to rescue Christians believed to be suffering persecution in the Iberian Peninsula. Bringing together the ideas of fighting for the faith and going to heaven for dying for the faith seems like an obvious thing to do.

Pope Leo’s letter is perhaps not as isolated as it may appear. Many of the papal letters preserved in the Codex Epistolaris Carolinus on Charlemagne’s orders in 791 contain suggestions that going to war on behalf of the pope could ensure one’s path to heaven. A particularly striking example appears in a letter of 756 sent by Pope Stephen II (r. 752-757) to King Pippin III (r. 751-768) and his sons, which purports to be the words of St Peter addressing the Franks. Stephen wanted Frankish help against the Lombard king Aistulf (r. 749-756). St Peter lists the crimes of the Lombards to the Franks before stating that he was:

Offering you the rewards of eternal recompense and the unending joys of heaven – provided that you have very speedily defended my Roman city and my own people, your Roman brothers, from the hands of the evil Lombards.

(Translated in McKitterick, van Espelo, Pollard and Price.)

There are some obvious differences with Leo’s letter. Peter/Stephen doesn’t state that the Franks would have to perish while on this campaign to enjoy this heavenly perk. More surprising is the target of this campaign, the Lombards being Christian, albeit not behaving particularly so from a papal perspective.

Despite these differences, this letter and others in the same collection offer a Carolingian context for Pope Leo’s exhortation to the Frankish army. Something similar appears in material celebrating Gerold, the Prefect of Bavaria, who died fighting the Avars in 799. Heito’s Visio Wettini from 824 declared that Gerold deserved ‘everlasting life’ because he died ‘in defence of the holy church against the infidels’. Fraser recently drew my attention to a sermon of Abbo of Saint-Germain from the 880s, translated by Charles West, which calls upon the listener:

Do not let your enemies multiply and grow but, as Scripture commends, fight for your homeland (patria), do not fear to die in God’s war (bellum Dei). Certainly if you die there, you will be holy martyrs.

I suspect that such ideas were not unknown elsewhere in the Carolingian world, but they might not have been commonly expressed. This is hinted by the fact that in 878 Pope John VIII (r. 872-882) had to reassure the bishops of the West Frankish kingdom that those who died fighting against pagans would go to heaven, suggesting that it wasn’t an idea that they regularly encountered. Likewise, the importance of Leo’s letter for the canonists was in large part the result of the absence of other authorities to draw upon. When Peter Comestor (d. 1179) sought to defend the point in a tract addressed to a Patriarch of Jerusalem, his only sources were Leo and Pope Urban II (r. 1088-1099).

Looking at c.3 of the letter alone makes Leo IV look like a solitary prophet of the age of the Crusades. The rest of the text however very firmly places him in the Carolingian world. This is a letter written by Leo to stiffen the spine of a Frankish army, and the consolations of heaven to the fallen is the very last argument he uses to steady the troops. He begins by emphasising the evil of the enemy, who are both inimical to the faith and the peace of all people (c.1). Interestingly, Leo addresses the men in the context of the history of the Franks in c.2, recalling to them the example set by their ancestors. In doing so, the Pope was probably doing more than reminding them of the formidable achievements of Frankish arms over the previous century and a half. He also implicitly harked back to the relationship between the Carolingians and the Papacy that stretched back to the days of Pippin and Stephen, in which the Franks protected Rome against all threats. The sack of 846 was a shocking moment for the Carolingians as well as the Papacy, prompting Lothar and, particularly, Louis II to pay much more attention to southern Italy. The latter would define his reign by his capacity to protect Italy and the Pope from Saracen threats. That bond was acknowledged by Leo as he steeled the Franks of his own day by celebrating the deeds of those long past.  

This may give us a clue for dating the letter. Louis II arrived in southern Italy with a Frankish army in 847, and spent much of 848 campaigning against Muslim pirates while trying to end the civil war that had riven Benevento, leading to the formal division in 849 of the troubled principality. He returned south in 852 to campaign against Bari. This suggests 847-8 or 852 as the most likely contexts for the Leo’s address to a Frankish army. Although it could be either, I’m tempted to go with the earlier date, simply because praising the efforts of the ancestors of the Frankish army seems like a slightly odd move if there had already been an expedition five years earlier in which some of the army of 852 had probably participated. By contrast, before 847 there hadn’t been a Frankish army south of Rome since the days of Charlemagne, a full generation earlier.

Even if we can’t pinpoint the exact year of the letter, we can locate it in a Carolingian milieu. Leo’s comments on the souls of those fallen in holy war were unusual for his period. They would go onto be highly influential in the very different circumstances of the Crusades. But by reading the entire letter as it survives to us, we can see it as the product of the Carolingian world, written not to be an example for lawyers, but as a rallying cry for desperately scared and fiercely proud men in a time of crisis.

All’s Fair in Love and Holy War: A Response to My Critic

One of the things that makes being an academic often seem slightly unreal is that you spend a lot of time feeling like you’re screaming into the void. You craft articles by conducting the research, honing the argument in conference papers, writing and re-writing variations of the same words over again until by some curious alchemy they are transmuted into something resembling coherence, before scurrying off to the library to get the last footnote just right. You benefit from/endure the advice of anonymous peer reviewers. You edit, and edit some more, and question your intelligence and sanity when at the very last minute you spot a ghastly spelling mistake that somehow escaped the ministrations of the past half year or more of work. At last, you finally place it into the journal’s online submission system, and away into the aether it goes. And then, if you’re anything like me, in the quiet moments in the middle of the night, you ask yourself whether there was in fact any point to the exercise, whether any of that work will make any difference, and if anyone, anywhere, will ever read your labour of love.

This is why my first emotional reaction to reading a chapter criticising my work was joy. In this piece, ‘Holy wars’? ‘Religious wars’?: The perception of religious motives of warfare against non-Christian enemies in ninth-century chronicles’, in the recent volume Early Medieval Militarisation[1], Professor Hans-Werner Goetz spends a couple of pages (pp. 214-216) discussing an article of mine (‘“Those same cursed Saracens”: Charlemagne’s campaigns in the Iberian Peninsula as religious warfare’, Journal of Medieval History 42 (2016), pp. 405-428). I think it’s fair to say that he’s not a fan of it. Nonetheless, the excitement of opening the volume, seeing my name in print and realising that someone somewhere had read my work and thought it worth their time demolishing it was very real.

My attention was drawn to this chapter for a couple of reasons. These begin with the fact that Hans-Werner Goetz is a major scholar whose work on medieval frontiers and perceptions of other religions I have greatly benefited from. But also, this isn’t the first time that my article has attracted the attention of Professor Goetz in print, having featured previously in his ‘Glaubenskriege? Die Kriege der Christen gegen Andersgläubige in der früh- und hochmittelalterlichen Wahrnehmung’, Frühmittelalterliche Studien, 59 (2019), 67-114, specifically at pp. 99-102. Given this, I thought it might be useful for me to take some time to respond to Goetz’ concerns, not least because he raises some interesting questions about the relationship between war and religion in the early medieval period.

The argument in my original article, which you can read in full here, runs as follows:

1. Charlemagne’s wars in the Iberian Peninsula, which include both the disastrous invasion of 778 and the campaigns conducted by his son Louis the Pious as king of Aquitaine in the 790s and 800s, are normally understood as secular affairs, opportunistic wars of expansion. This is because the most important primary sources, particularly the Royal Frankish Annals, don’t depict them as religious conflicts.

2. This is quite striking when compared to wars against other non-Christian neighbours such as the Saxons, where Charlemagne deliberately targeted sites of worship such as the Irminsul and forced the population to convert to Christianity at the point of a sword, imposing multiple laws defining what it meant to be a Christian.

3. However, by looking at a wider range of sources that relate to Carolingian warfare in the Iberian Peninsula in this period, we can see a more complicated picture, where defending and even expanding the Christian faith are key motives for these campaigns. These sources are:

  • a. The Continuations of the Chronicle of Fredegar, compiled during the reign of Charlemagne’s father, which celebrate his ancestors in their wars against Muslims.
  • b. A letter of Pope Hadrian I to Charlemagne discussing the 778 expedition.
  • c. The liturgies of war contained within the Sacramentaries of Gellone, Angoulême and Arles.
  • d. Charters from Charlemagne, granting land to the Hispani on the Spanish March in about 780 and 801.
  • e. A letter of Alcuin from around 790 concerning Charlemagne’s expansion of the Christian world, including in the Iberian Peninsula.
  • f.  A poem by Theodulf from 796 calling upon Charlemagne to bring the Arabs to Christ.
  • g. A letter from Charlemagne to Bishop Elipandus of Toledo from around 794, saying that he had sought to liberate the Christians of al-Andalus from Saracen rule.
  • h. Ermold the Black’s praise poem of Louis the Pious (written 824-6), which has Louis declare that if the defenders of Barcelona in 801 were Christian, there would be no need for him to go to war against them.

While individually each would be a thin reed to base an entire argument, in accumulation they become increasingly convincing.

4. Based on these perspectives from within and without the court, Frankish wars in al-Andalus in the reign of Charlemagne can be characterised as holy wars, because they were presented as wars to protect and expand the Christian church in Francia and in the Iberian Peninsula. This does not mean those were the only motivations for those conflicts, but they were a major one, and the dominant explanation provided in contemporary or near contemporary sources.

5. I speculate that the reason the annals avoid much of this religious language is that with the exception of the capture of Barcelona in 801, the majority of the campaigns in the Iberian Peninsula did not go particularly well. While this was never desirable, it was particularly embarrassing if you had previously raised the stakes by making it a war of faith. Therefore, annalists linked to the court played down the religious fervour that surrounded the expeditions.

As mentioned above, Hans-Werner Goetz has disagreed with this article in two separate publications. Both resemble each other closely, often sentence-by-sentence and footnote-by-footnote, so unless specified I’m going to treat them as the same text. His broad argument is that the category of ‘holy war’ is not a meaningful one in the early medieval world, because all of culture and society was so imbued with religion that there was no other type of war. All conflicts were justified and legitimised by the faith so the idea of a war of religion is a modern anachronism. This is an idea I find extremely interesting and which I want to discuss later.

However, Professor Goetz has also disagreed with my article on more specific grounds and, with your indulgence reader, I would address them first, if only because anyone who read his pieces would fairly walk away under the impression that I am a poor scholar indeed. But let’s start with places where we both agree. Goetz begins by saying that my work ‘still pre-assumes (setzt voraus) that Charlemagne’s wars were religiously motivated’. Basing my work on assumptions would indeed be unfortunate. However, prior scholarship for several decades tended to assume the opposite, and it was this prior scholarship which the case that I made was responding to. The professor also notes that ‘the fact that the Saracens are recognised and judged as non-Christians’ is not proof that wars against them were holy wars. I agree! My argument was that the apparently ‘secular’ ethnic labels often used in the sources such as ‘Saracen’ or ‘Agarene’, were in fact imbued with Biblical significance, implying that they were non-Christian and antithetical to Christianity; but this was not meant to be evidence for holy war, but rather against standard arguments that the language of the annals is secular on the matter. In the longer German treatment, Goetz argues that we cannot use the religious motivations that the biography of Louis the Pious written by the anonymous author known as ‘the Astronomer’ attributes to Louis for his campaigns against al-Andalus, because they are too late. I agree and did not use it in my article for precisely that reason.

Turning to the pieces of evidence underpinning my argument listed under point 3 above, Goetz only mentions b, c, d and g; and I will deal with these in order. With regards to Hadrian’s letter to Charlemagne on the eve of the campaign of 778 (b), he argues that the Pope’s language comparing the Saracens to Pharaoh in the Bible says nothing about his motivations and was applied to every war. I disagree. The reference to Pharaoh is relevant because Hadrian notes that the reason he and the Egyptians drowned is because ‘they did not believe in God’. Charlemagne will triumph because he is Christian and the Saracens are not. Goetz’ argument is not strengthened by the examples of other wars he himself lists where similar comparisons were made. These include the statement in the Life of Bishop Athanasius of Naples c.7 that God helped the people of Naples defeat the Saracens and cast them down like Pharaoh. However, insofar as this language is also being used to describe non-Christian enemies this comparison would seem to support my case better than his. The other examples listed in fn.193 of the German article are all considerably later but also don’t strike me as entirely convincing in this context. Henry of Latvia describing the conversion of Baltic pagans as being akin to the casting down of Pharaoh does not scream secularity to me. I am not intimately familiar with Otto of Freising or William of Newburgh and so won’t comment on them. Nonetheless, I would argue that two of the four examples which Goetz chose to prove that comparisons to Pharaoh did not have connotations of holy war actually do look like precisely that. 

Goetz also dismisses the sacramentaries (c), writing that ‘people prayed to God for assistance before every war’. This is true, but not every sacramentary contains a mass specifically for wars against non-Christians, in the case of that of Gellone against ‘the infidel people’, in that of Angoulême ‘the pagans’. These are highly unusual masses, and in the case of the Sacramentary of Arles, the relevant mass had to be added to the manuscript at a later date than the other liturgical texts. All three of these sacramentaries are to be located in Aquitaine or Septimania, where the most likely non-Christians to be encountered were Muslims. That of Gellone may have belonged to Count William of Toulouse, who spent much of his career battling al-Andalus.

Nor is Goetz impressed by the charters (d), stating that ‘the granting of charters and donations to individual followers is a completely normal procedure’. In this case, though, what is significant is the unusual content of these documents. Charlemagne explains that he is giving the land because the recipients have had to flee the oppression of the Saracens in their homes in al-Andalus. The reason they are oppressed is that they are Christian, and the Saracens are ‘the enemies of the Christians’. The reason that Charlemagne is helping them is because they are his fellow Christians and they take part ‘in the unity of the faith’. In turn, they would perform military service, fighting with Charlemagne against their shared enemy the Saracens, who were their enemy because the Saracens hate Christians. This is strengthened by a charter from the 790s which rewards a soldier named John with land because he had killed ‘the heretic or infidel Saracens’. In fn. 49 (fn. 197 of the German article), Goetz claims that I explain the presence of Arab or Berber sounding names among the charter beneficiaries as ‘a misconception of the scribes’. However, my argument was somewhat different: I suggest that this points to the possibilities for nuance and complexity, where grandiose rhetoric and ideology meet reality. I don’t think even the most hardcore scholar of holy war would doubt that there were places where lines blurred at the edges, as any historian of the crusades could tell us.

In the longer German treatment, Goetz states that Charlemagne was more concerned with heretics than with non-Christians. This refers to Charlemagne’s letter to Elipandus (g), where the Frankish king informs the Adoptionist bishop of Toledo that whereas before he had striven to save them ‘from worldly bondage’, that is, being ruled by Saracens, but now that he knows they are heretics, he will leave them to their fate. Moreover, in this letter Charlemagne claims that his motivation for his earlier wars against al-Andalus, including the invasion of 778, was to save the Christian population, his co-religionists, who were being oppressed because of their religion. If that’s not a religious war, I don’t know what is. Further, Charlemagne’s statement that he felt less inclined to wage war on the Saracens now that he knew he wouldn’t be saving his fellow catholic Christians again seems to me to fall on my side of the ledger.

Goetz finally observes that in 778 Charlemagne treated the Muslims of Zaragoza gently, while sacking the Christian Basque city of Pamplona. The reason Zaragoza got off lightly is that Charlemagne didn’t conquer it. It was never in Carolingian hands. The ruler, Husayn al-Ansari, refused to let the Franks in and they were balked by the mighty Roman walls of the city. Pamplona may have been sacked because it was perceived to be in rebellion, something Charlemagne was never gentle in his dealings with. In any case, as the ignominious example of the Fourth Crusade demonstrates, religious military campaigns can be vulnerable to mission creep.

Roland duels the giant Ferragut in an illustrated Grandes Chroniques de France (source)

Having said all that, Hans-Werner Goetz does raise an interesting point. Religion suffused medieval society to the point that it was the air that it breathed. Kings begged for divine aid in their endeavours and sought the help of their advisors who were learned in such matters. Spin doctors legitimised conflicts as being pleasing to God, encouraging people to believe that their cause was just and that they would triumph. Those engaged in battle beseeched the heavens for survival. He also notes that unlike the idea of a ‘just war’, there is no clear category of ‘religious war’ in the sources.

To take the second point first, while avoiding anachronism is an important part of comprehending the past, historians apply categories and ideas familiar to us but unfamiliar to the period all the time when it helps us to analyse and understand the past in ways that the people who wrote our sources were not consciously able to. A nice example here is economic history, which uses methods and concepts developed by modern economists in order to build up a sense of how resources, labour and exchange interacted to underpin the medieval world in ways that would not have been articulated at the time, but which reveal something real about the period that we can use. This applies to other topics related to the world of ideas and identities. Studying subjects such as gender and sexuality requires that we both understand the way they were categorised in the past and relate them to our own concepts in the present. Sticking purely to the intellectual constructions we find in our sources traps us in the worldview of the sorts of people wrote those sources. Those include few women, poor people or slaves. To get their history, our history, the history of the vast majority of human beings alive at the time, we need to be able to read our sources against the grain, and to ask questions which cut across the purpose and mindset of their writers.

But I would also suggest that there are points where we can in fact see people from the early middle ages categorising a particular war as specifically religious. When Pope Leo IV exhorted a Frankish army in 852 going to war against the Saracens, he famously promised them ‘that the kingdom of heaven will be given as a reward to those who shall be killed in this war’. This was because they were ‘fighting for the truth of the faith and the salvation of the soul, and the defence of the country of the Christians’. The Pope draws an implied distinction between this type of war and other types of wars. Unlike other campaigns the Franks might find themselves on, this one would see them win the ultimate prize because they were fighting for a holy cause. The same point was made by Pope John VIII in 878 in a reply to the bishops of West Francia who had asked for clarification on this. John wrote ‘those who, out of love to the Christian religion, shall die in battle fighting bravely against pagans or unbelievers, shall receive eternal life’. The Pope emphasises that this is because of the nature of the cause and of the enemy being fought. Again, this distinguishes between a religious war and other sorts of conflict.

The statements made by Leo and John are old chestnuts in scholarly circles because it is unusual to have anyone be this explicit on the matter in the early medieval world. But we might also be able to identify holy wars by the behaviour of those who undertook it. There were any number of possible reasons that Charlemagne might want to conquer the Saxons that would not involve religious motivations, ranging from a desire for a more secure frontier, military glory or expanded resources. None of those explanations would require the Frankish king to destroy Saxon cultic sites or forcibly convert the population to Christianity. Such a policy was if anything more likely to inspire resistance and rebellion. His father, Pippin the Short, had not felt the need to do such things when he invaded Saxony in 747 and 758. The way Charlemagne prosecuted the war against the Saxons was specifically shaped by his motivations. This was a holy war in a way that Pippin’s had not been, and his behaviour and that of his men and his opponents was different because of it.

This is where I think the concept of ‘holy war’ comes in useful, because by identifying it as a meaningful category, we can use it to draw up hypotheses and make predictions about people in the past. This is not to say that all religiously driven warfare was the same, or that all people involved in it had no other motivations. The past is complicated. People are complicated. But, by having ‘holy war’ in our tool box, we can understand and interpret patterns of behaviour that would be otherwise baffling if we didn’t have it.

I want to close this post by expressing my gratitude to Hans-Werner Goetz. If he had not taken the time to seriously consider and respond to my work, I might not have been motivated to think about this topic in this way, and clarify in my own mind why ‘holy war’ strikes me as an interesting and meaningful topic. Scholarship makes better progress through friction. So thank you, Professor Goetz, for making me feel less like a voice screaming into the void.

[1] Edited by Ellora Bennett, Guido M. Berndt, Stefan Esders and Laury Sarti (Manchester: Manchester University Press, 2021).