Two answers required. One of these two powers constructed “the Beauteous Fortress” during a campaign in which Marshal de Boucicaut (“boo-see-COH”) aided the other. One of these empires tried to form an alliance with the Ilkhanate ruler Mahmud Ghazan to fight the other after the Battle of Bapheus. Fighting between these two empires destroyed the Hexamilion wall. During an incident between these two empires, one of them refused to follow John Kantakouzenos’s orders by continuing to settle Gallipoli. An emperor supposedly turned to marble after a siege between these two empires (10[2])that caused the fall of the Paleologos dynasty. (10[1]-5[1])For 10 points, (10[1])what two empires fought each other during the 1453 siege of Constantinople? (10[1])■END■ (10[3])