The Crusades were a series of religion-driven military campaigns waged by much of Christian Europe against external and internal opponents. Crusades were fought mainly against Muslims, though campaigns were also directed against Slavs, Jews, Russian and Greek Orthodox Christians and political enemies of the popes.

The Crusades originally had the goal of recapturing Jerusalem and the Holy Land from Muslim rule and were launched in response to a call from the Eastern Byzantine Empire for help against the expansion of the Muslim Seljuk Turks into Anatolia.

The forces of the knights and nobles who came from France, Germany and other areas in Western Europe numbered about 30,000. After a war that lasted three years, the 12,000 surviving Christian fighters began a five-week siege of Jerusalem. They captured the city after a battle that was so fierce that the streets were described as running red with blood.

The Christians had recaptured the Holy Land. This victory lasted for less than 90 years, however. Jerusalem was captured again by the Muslims. Several more Crusades were attempted, but in the end, they were failures. When the Crusades were all over, the Holy Land remained in Muslims¡¯ hands.

The people who decided to go on the First Crusade had many motives. Faith and the desire to make the Holy Land Christian again were the principal driving forces. Some people who went on the First Crusade certainly understood that they might get more land and acquire more wealth. Some wanted to go for the sheer glory and adventure of it. Others believed that their sins would be forgiven. Some merchants saw the possibility of more trade and profit.

The Crusades stimulated an interest in travel which began to end the isolation of Europeans from the outside world. This led to changes in European life. In particular, Europeans were attracted to the products of the Middle East. Sugar replaced honey as the principal sweetener. Pepper, cinnamon and other spices became common. Silk and cotton were very much in demand. Foods such as rice, peaches, lemons, cherries were all introduced into European life.