And they're able to maintain control through these crusader kingdoms all the way until 1187 when Salah ad-Din is able to retake control of Jerusalem. Then a few decades later as we go into the Sixth Crusade and the Barons' Crusade, which isn't depicted here, the Western Europeans are able to take more control, but eventually the Muslims take control of Jerusalem, and as we enter into the 14th century, they have control of the entire Holy Land. Now while that is happening, Constantinople gets sacked at the end of the Fourth Crusade by the crusaders themselves, and even though it's retaken, this is really the beginning of the end for the Byzantine Empire. So let's think a little bit about how the Crusades changed Europe and the entire world. Well, one of the obvious impacts of the Crusades was just the amount of death it caused. It's estimated that the death toll from the Crusades is two to six million people just from Western Europe, and just to put that into perspective, the European population at the time was about 60 to 70 million folks. So we're talking about four to 10% of the population dying in the Crusades, and this isn't fully accounting for all of the death and destruction that happened on the way to the Crusades or that happened in the Middle East as well.