So you'd think this disaster would discredit the whole notion of crusading, right? No. Instead, it legitimized the idea that crusading didn't have to be about pilgrimage, that any enemies of the Catholic Church were fair game. Also, the Fourth Crusade pretty much doomed the Byzantine Empire, which never really recovered. Constantinople, a shadow of its former self, was conquered by the Turks in 1453. So ultimately, the crusades were a total failure at establishing Christian kingdoms in the Holy Land long term. And with the coming of the Ottomans, the region remained solidly Muslim, as it mostly is today.