The Crusades were a series of religious wars directed and initiated by the Church and Pope in the medieval period. The term refers especially to the Middle Eastern wars between Christians and Muslims in the time between 1096 and 1271 in attempt to recapture Jerusalem.
Jerusalem was a city of religious significance to the Christians, because it was supposedly where Jesus Christ preached the Christian God’s ways, was crucified and resurrected, so, they wanted control, so, that they could preserve and visit these sites constantly.
However it is also a symbolic city to the Jews, as, inside the city is a temple named the Dome of the Rock, inside which was the Holy of Holies, the most sacred site in Judaism. Many Jews believe that this was the location of the foundation stone from which the world was created.
But, there are three religions fighting over this sacred city: and the last one is the Muslims. This site is sacred to most Muslim people as it is where prophet Muhammad ascended to heaven.