The Crusades gave kings and the pope opportunities to expand their bureaucracies. They also provided kings with the perfect opportunity to get rid of troublemaking knights, particularly restless younger sons. Even some members of the middle class who stayed at home profited from the Crusades. Nobles often had to borrow money from city residents to pay for their expeditions, and they put up part of their land as security. If a noble did not return home or could not pay the interest on the loan, the middle-class creditor took over the land.

The Crusades introduced some Europeans to Eastern luxury goods, but their immediate cultural impact on the West remains debatable. Strong economic and intellectual ties with the East had already been developed by the late eleventh century. The Crusades did greatly benefit Italian merchants, who profited from outfitting military expeditions, the opening of new trade routes, and the establishment of trading communities in the Crusader states. Since commerce with the West benefited both Muslims and Europeans, it continued to flourish even after the Crusader states collapsed.

The Crusades proved to be a disaster for Jewish-Christian relations. In many parts of Europe, Jews lent money, and indebtedness bred resentment. Inspired by the ideology of holy war and resentment of Jewish economic activities, Christian armies on their way to Jerusalem during the First Crusade joined with local people to attack Jewish families and sometimes entire Jewish communities. In the German cities along the Rhine River, for example, an army of Crusaders under the leadership of a German noble forced Jews to convert through mass baptisms and killed those who resisted; more than eight hundred Jews were killed in Worms and more than a thousand in Mainz. Later Crusades brought similar violence. As a result of growing hostility, legal restrictions on Jews gradually increased throughout Europe. In 1290, King Edward I of England expelled the Jews from England, and King Philip IV of France followed Edward’s example in 1306. The Crusades also left a legacy of deep bitterness between Christians and Muslims. Each side dehumanized the other.

At the same time, the Crusades shaped the identity of the West. They represent the first great colonizing movement beyond the geographical boundaries of Europe. The ideal of a sacred mission to conquer or convert Muslim peoples entered Europeans’ consciousness and became a continuing goal. When Christopher Columbus sailed west in 1492, he hoped to reach India in part to establish a Christian base from which a new crusade against Islam could be launched.