Conquest in the Middle Ages was always difficult. Even the greatest kings found collecting resources complicated and persuading followers problematic, which is why it was usual to try to come to terms with the existing population. Distance, geography and weather made the process complex and liable to miscarry. Yet in 1095 a pope, Urban II (1088-99), proposed a military expedition to seize the city of Jerusalem, some 4,000km distant from Clermont where he was preaching, in a land strange to most of his listeners, with a climate they would find harsh, occupied by people of an alien religion who would brook no compromise. There was no great leader with a retinue of predatory followers to take command, and he offered no pay to those who went. What was proposed appears as ideological warfare in the purest sense: that men should leave their riches, their wives and their lands to free Jerusalem from the infidel, thus gaining an indulgence - release from the burden of sin - and, if death should overcome them, immediate entry into the kingdom of heaven.
It is strange is that such an idealistic appeal should be directed to a class whose primary preoccupation was landholding by one who was, after all, drawn from their ranks. What is even stranger is that it succeeded, for the First Crusade brought together an army of over 60,000, including in its ranks 6,000-7,000 cavalry drawn from the ranks of the leaders of society. 1 But this is not such a great paradox. Men and women did not make their decisions, even about peace and war, solely on the basis of proprietorial considerations - it was simply that in any serious matter these played a major, and often the major, role. It would be an impossibly narrow view of human motivation to believe that it was always entirely material. Moreover, and this is critical to our understanding, the Crusade was presented in a way which had a powerful appeal to the proprietorial instinct.