The Crusades: defensive wars?

Recently experts on the Crusades have got a reasonable amount of press on whether the Crusades should be condemned or not. One statement made by several of them is that the Crusades were justifiable as defensive wars against Muslim aggression.

Iff you look at maps illustrating the course the Crusades, you usually will see a fairly clear back-and-forth boundary between Christian ruled countries and Muslim ruled countries.

Yet I have a hard time taking this argument all that seriously because I have my strong doubts that warriors in the 11^th century, whatever the ethnic or religious background, cared whether or not a war was “offensive” or “defensive”.

If you look at the 11^th century, the century that ended with the First Crusade, and you will find a large number of major wars that resulted in new rulers being imposed on the previous population, which sometimes practiced a different religion from the conquerors. Here is an incomplete list straight out of my head, done without referring to any reference works so there might be some mistakes. It is in roughly chronological order.

• Conquest of England by Knut (Canute)
•  Conquest of Norway by Canute
•  Conquest of England by William
•  Conquest of southern Italy and Sicily by various Normans
• Conquest of Anatolia by the Seljuk Turks
• Conquest of Central Spain by Castile
• First Crusade

Similarities

• It is extremely unlikely that any of the conquering armies saw themselves as ethnically or nationally unified. In some cases it is quite clear that they were ethnically heterogenous.
• People were willing to travel long distances to take part in wars that might result in conquest. 
• Also, it is pretty clear that warriors believed that if they were successful in their war they were entitled to all the wealth that they could confiscate, whether that might be lordship over wide territories for the highest ranking and most successful or whether it might be plunder, which just about everybody expected and hoped for.

Using this perspective, The First Crusade doesn’t seem to be all that different from the other wars listed here.

That doesn’t mean other reasons for wars were not present. William the Conqueror seems have considered himself to have been legitimately named as Edward the Confessor’s heir for the kingdom of England. Some of his followers may have gotten a bit of a thrill from fighting for the right of William to be King. But they did not go home after Hastings to sit around talking about how they had done the right thing. No, they got as much territory and profit out of William’s successful war as they possibly could. Also, the Pope did give William a papal banner to take to England as a sign of ecclesiastical support and a certain amount of religious justification was present in some of these other wars as well. Some people did go home after the first crusade and talk about how they done the right thing. But what plunder could be acquired was always part of the picture. It was a rare warrior – were there any? – who did not think that plunder was a legitimate source of profit in any war.

Visualizing these large groups of armed men roaming the countryside stealing stuff and conquering countries makes me sceptical that the big movements on the historical maps of the Crusades can be explained as “defensive wars.” Looking back over the larger sweep of history I wonder whether “defensive wars” were an important phenomenon in most people’s view of the world before the 20^th century. Certainly professional warriors have tended to look at war as a normal part of life, not some terrible breakdown of society as many people feel today. Perhaps a dislike for war was stronger among non-warrior groups such as the peasantry or the clergy (especially monks) and of course large numbers of women. But among the people who led wars and fought wars, did they really think about offense or defence as an important category affecting their decision-making?