Medieval Crusader Theology

Hello, Let me just start by saying sorry if this is in the wrong forum. I wasn’t quite sure where to put it and moral theology seemed closest.

I’m currently trying to find some sources to read that provide theological arguments for crusading, especially works that were produced in the High Middle Ages and came from clerics or official Church authorities.

I often see arguments against crusading, but I’m trying to find out what the Church’s actually theological argument for the practice actually was at the time. Some chronicles and epics do have short justifications of crusading, but they tend to be in the form of ‘We’re doing God’s work! We must be right!’ as opposed to actually giving real theological arguments. The records of Urban’s speech are a little more helpful (for example in Fulcher of Chartres’ work), but tend to focus on the immediate causes (i.e. Byzantines being defeated) rather than the theological side of things so much.

On a related note, I’m also looking for Church sources which are in defence of the military orders. For instance, I understand that the official Church position is that the Templars were wrongly persecuted as the Church was forced into it by the French. However, I don’t actually have any idea where this is officially stated.

I’m sorry if this is all a bit much to be asking you all, I’m just hoping for some help on where to look for the Church arguments for these things. The best place I’ve though to look would be the Papal Bulls, but a quick look at (as an example) Pie Postulatio Voluntatis (which gave official backing to the Hospitallers) seems to show a lack of theological discussion. I also can’t find the text for some of the Templar Bulls, rather annoyingly. Quantum praedecessores (calling for the Second Crusade) is a bit more useful, insofar as it says ‘this is why we need to crusade this time’, but I still feel it’s a little short of what I’m looking for.

As a quick aside, does anyone know if you can buy a book/collection etc of all Papal Bulls up until now? I had a look and some can’t be easily found online.

Anyway, I’ve rambled on a bit now and asked a few questions that hopefully someone here can help with. I would awfully appreciate any help.

TLDR Need sources that give official Church theological arguments for the crusades and the military orders.

Thank you!

:eek:Well, I hope someone answers you! I’d have to google for awhile to answer that one but surly there is someone who will soon be writing you. :rolleyes:

Hopefully! :smiley: Thanks for taking the time to reply anyway!

I only know a little about it. I know that the first crusade was in direct response to pleas from Christians whose land was being conquered by Muslim armies. I wish I could remember the name of the great book on the topic I’ve been told about, or even the author. I know it’s available on the shop portion of this site ( ) If I can think of the author or title I will let you know. I’ve heard the author talk about the subject a few times now. There is also a great cd on the topic from lighthouse Catholic media if I recall correctly.

I don’t know if there is a collection of papal bulls. It would be an interesting read.

Was it ‘Catholic Controversies: Understanding Church Teachings And Events In History’?

I don’t believe it’s that one. The one to which I am referring was specifically about the crusades. I think that I have heard of the one you mention though. I should have written it down. I listen to a lot of Catholic radio, and I have heard this guy a few times there. The one you mention sounds like it might have some answers for you though. Anyway, the crusades got way out of hand and most of the later ones weren’t authorized by the church.

‘The Glory of the Crusades’? I’m Just trying to see if I can find what you’re talking about in the shop.

I think the crusade ideal was ‘good’, but you’re right, some of them were very far from holy endeavours.

Here are several primary documents that have some helpful indications of just war theology among the Crusaders.

St. Bernard - In Praise of the New Knighthood

This one is particularly helpful because it was written specifically about the Templars. St. Bernard composed the monastic rule for the Templars, and in this document he defends his institution from the charge that monks should not fight. He gives several arguments for why it is just to fight in the Crusades, and as a sample here is a line from Chapter 3: “But the Knights of Christ may safely fight the battles of their Lord, fearing neither sin if they smite the enemy, nor danger at their own death; since to inflict death or to die for Christ is no sin, but rather, an abundant claim to glory.”

He goes on to cite Scripture and theological texts in favor of just warfare and discusses how this particularly applies to his new order, the Templars.

Letters of St. Bernard Promoting the Second Crusade

This contains his letters to Bavaria, England, and Archbishop Henry of Mainz. The letters mostly use the defense of Christians as a reason to go to war, which satisfies one of the criteria of just war.

Pope Alexander II on Just Wars against Muslim Spain

Pope Urban II’s Speech on the First Crusade - Robert the Monk’s Version

Pope Urban II’s Speech on the First Crusade - Fulcher of Chartres’s Version

St. Thomas Aquinas on Just War

Additionally, I have a page on my website that discusses Catholic military history in every age from the 100s to the 1000s:

Catholic Military History

I haven’t gotten to the Crusades yet, but that page contains short descriptions from historical accounts of the various wars of Catholic history along with descriptions of the just war doctrine from every age.

I hope that helps. Please let me know. God bless!

I’ve come across St. Bernard of Clairvaux’s In Praise of the New Knighthood, but never read it before as I was totally unaware it was about the Templars! Just read it through and it’s absolutely excellent, thank you. I assume his letters will be just as helpful.

I also just read the extracts from Pope Alexander II’s letters, fascinating how he is commending them for the defence of the Jews.

I’ve read a number of versions of the Clermont speech, but thanks for including them. A quick look tells me that I ought to reread them anyway to refresh me memory. Serves as a good prod to get me going back over them!

I’m vaguely familiar with Thomas Aquinas’ Just War Theory, although I’ve never read the Summa.

Your website looks like it’s a great resource, I’ll take a closer look in a bit and I’ll be especially looking forward to the crusades articles!

I’ll do some more reading later and let you know more! I’m eager to dive into everything you’ve suggested, but I’m going to collapse unless I go to sleep soon haha

Thanks so much for your help and don’t hesitate to suggest anything else!

Well, I hesitated to include the following resource because I initially forgot about it and then subsequently I realized how difficult it is to access. But Gratian’s Decrees is very important on this issue. Not only was it in use as a textbook in the universities, but it was also one of the highest authorities for canon lawyers of the time. And it includes a whole chapter on just war.

The chapter in question is Part 2 Causa 23. It is difficult to access that chapter in English for free online. But I have found one way:

First, log in to an account at You might need to create one if you don’t already have one. You’ll need this account to access a more in-depth version of Amazon’s “look inside” feature in their previewable books.
Second, go to the Amazon page for the book The Ethics of War. This book has a translation of Causa 23 from Gratian’s Decrees. They included it because it was the best medieval canon law textbook on just war and it was used throughout the 1100s and 1200s.
Third, click “Look inside.”
Fourth, use the “Search inside this book” feature to search for the word “causa” << notice that it ends with an a, not an e.
Fifth, click page 109, which is where the translation of Causa 23 begins.

I used to be able to go directly to that page, I think, but now it appears to limit me only to page 111. Anyway, you can get a good bit of his info right there. And I think it is another good example of what you are looking for.

I am just now beginning to read “The Glory of the Crusades” by Steve Weidenkopf. It’s a recent book of course, but I noticed that it has an extensive bibliography which might be useful for those wanting to do more reading. One thing for sure, it’s a mistake to view the crusaders as if they had the mindset of our time. Here is a short review for Patheos:

I think that’s the one. I was going to ask you who the author is, but someone else mentioned his name, and that sounds right to my memory. I’m looking forward to checking out the links which another person posted. They sound fascinating.

Steve Weidenkopf also has “The Real Story of the Crusades” on CD and MP3 here.

I have that CD set, it’s pretty good. I also have a Lighthouse Catholic Media CD by Dr Thomas Madden at St Louis University. He was the only living American Crusades specialist (with a book written) when 9/11 happened.

His Lighthouse Catholic Media cd is called Understanding the Crusades. You can get that here:

If you get Dr Madden’s book, make sure to get the revised edition of his book.

I believe both of the CDs, esp Steve Weidenkopf’s, list other sources to learn more about the truth of the Crusades.

God Bless!

I would look into the CHURCH’S call for the crusade…not necessarily what PEOPLE did.

If the church called for a crusade (which I believe they called for less than half that occurred) it was called to be conducted within the teachings of the church. So any “war crimes” or similar such things would be the wrongful act of people and essentially not congruent with what the church was actually about.

Myths about the crusades

One only has to look at where Christianity is today in the middle East. It’s at best on life support. Imagine this, the seedbed of Christianity is barely 1% of the total population there today… WHY? Christians just didn’t disappear or move out?

Just war clause would apply though too back then, so if the crusaders killed or did other things in times of battle, they would not be responsible for the sin aspect of it…that is if the reason for the crusade was indeed just.

The same thing would apply today if the CC ever called for this again, as long as the cause is just, they would be allowed to do these things, although if the church did this in our times, (when they probably do have good reason with abortion alone), I doubt many folks would join or be involved, and I really think most ‘catholics’ would take the opposing side (secular authority Im guessing), just for the sake of their own freedom and quality of life, so while they would be catholics, they just would not be willing to be christian to that degree.

Not sure if it’s particularly within the scope of your question, but Rodney Stark’s God’s Battalions provides an interesting apologetic for crusading.

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