In what year did the fourth crusade begin and end?

The Fourth Crusade began in 1202 with the blessing of Pope Innocent III to free the Holy Sepulcher and Jerusalem. Having agreed with Venice for help, the army of the crusaders was dragged by this state into a conflict with the Byzantine Empire. As a result, the crusaders took Constantinople in 1204, despite the Pope’s protests. When, in 1204, he received a message from the Crusader leader Baldwin, the Pope accepted the take and blessed the bishops and new flock of the Western Church. The Latin Empire was created in the territory occupied by the crusaders.