The Crusades were Christian military expeditions undertaken between the 11th and the 14th century to recapture the Holy Land from the Muslims. The causes of the Crusades were many and complex, but prevailing religious beliefs were clearly of major importance. The Crusaders continued an older tradition of the Pilgrimage to the Holy Land, which was often imposed as a penance; now, however, they assumed a dual role as pilgrims and warriors. Such an armed pilgrimage was regarded as a justifiable war, because it was fought to recapture the places sacred to Christians. Jerusalem had been under Muslim rule since the 7th century, but pilgrimages were not cut off until the 11th century, when the Turks began to interfere with Christian pilgrims. For Christians, the very name of Jerusalem evoked visions of the end of time and of the heavenly city. To help rescue the Holy Land fulfilled the ideal of the Christian knight.

By a slow process the local clergy and monks obtained a firm hold on the minds of the population of Western Europe. Through them the popes exercised stronger power than any ruler of their day. Toward the end of the 11th century, Pope Urban II could undertake an international policy for the church such as his predecessors might have dreamed of but could not have thought possible. He called for a crusade. A tremendous emotional movement began, where men and even children set out to recapture Palestine and to make it into a province of the Roman Catholic Church. These people were horrified, now that it was insistently called to their attention, that the sepulcher of Jesus should be in the hands of unbelieving Mohammedans, and they were willing to sacrifice themselves for its redemption. Before long the crusaders began to argue that it was ridiculous to go forth to kill God's enemies in a distant land while the Jews close at hand, equally opposed to Christianity, were left behind unharmed. Soon the cry was heard, "Kill a Jew and save your soul!"

There were several differences between the previous persecutions and those that followed. The former ones had been temporary, and usually initiated by the head of state. Therefore, they had been executed with a minimum of cruelty, for those days, and were soon repented for. Once it was over, the Jews could resume their lives. The persecution during the 1st Crusade in 1096 however, was the first of a long series. The emotion of hate upon which it was based was kept alive by generation after generation of priests and monks, either because of sincere but narrow religious zeal, or because attacking the Jews proved to be a sure means of self advancement.

The events of 1096 took place along the Rhine River, in most of the German states. There, the Jews were at peace with the local nobility and bishops, but in the end it was all the same. When the crusading bands arrived in town, the mob there invariably joined them. The middle class Christians, although sorry to see their Jewish fellow citizens suffer, refused to risk their lives in defending the Jews like they had promised. The Jews defended themselves and sometimes temporarily beat back the attacks; but it was a hopeless struggle against great numbers of armed enemies. In some cases, Jews saved themselves by Baptism, but the majority preferred to die with the cry of Shema' Yisroel upon their lips. Altogether, some ten thousand Jews lost their lives in Central Europe.

This loss of life and property resulted in a permanent change in the position of the Jew. But the chief obstacle in the way of returning to former conditions was the fact that the mind of the common people had been so poisoned as to believe that it was pleasing to God to kill a Jew. The second Crusade in 1144 would no doubt repeat the events that took place in 1096. St. Bernard, the most respected churchman of his day, came forward with a denunciation of those monks and priests who were urging the murder of the Jews. There were still many attacks upon the Jews, but due to St. Bernard's intervention and the better organization of the forces during the Second Crusade, these attacks were comparatively mild.

In 1189 another crusade was preached. By this time, attacks upon the Jews in France and Germany did not require the frenzied emotions of a crusade to start them. They had become a frequent occurrence, requiring only a slight pretext. Jews had settled in England about the time of William the Conqueror, and for a century had lived in peace. The trouble started on the day of the coronation of Richard the Lionhearted, when rumor spread that the new king had ordered a attack on the Jews. A few days after Richard's departure from the country, the riots broke out afresh. The reason for his is significant. The ringleader of the attacks and a number of his followers owed money to some of the Jews.