text: In 1187 , Saladin defeated the armies of the Crusades at the Battle of Hattin , largely because he was able to cut the Crusaders off from the valuable fresh water of the Sea of Galilee .
simplified: In 1187 , Saladin defeated the armies of the Crusades at the Battle of Hattin , mainly because he cut the Crusaders off from the valuable fresh water of the Sea of Galilee .