4th July 1187 - The Horns of Hattins

Coalition forces of Outremer states and Crusading orders were decisively crushed by Ayyubids forces led by Salah ad-Dīn, resulting in the fall of Jerusalem and the lauch of the third crusade. The battle is featured in many movies and are playable in games such as Medieval: Total War, Age of the Empires II and Stronghold Crusader.