Well, the Crusades were over a great period of time. The first Crusade began in 1096 and ended in 1099CE. the fourth Crusade began in 1202 and ended in 1204 CE. But you also can't forget the final Crusades (they were not as big as the other crusades, hence the name not being in detail.) The final Crusades were from 1217-1272 CE. As you can see, the crusades went on for years.....
