Only to invade it for themselves in AD 1204 during the 4th Crusade where prostitutes and horses were brought into our Hagia Sophia, various Uniate churches established to undermine the authority of the Orthodox Church, and a multitude of our relics including the Shroud of Turin were stolen for the Vatican. The Crusades weren't just a series of war between Western Christendom and the imperialistic Islamic menace; they were wars against Orthodox Christendom which was victimized by both sides of the conflict.