The Palaeologan emperors hoped to preserve their shrunken realm with Western aid but could not stop the Ottomans. The last emperor, Constantine XI, and his 7,000 gallant comrades went down fighting as the historic capital of the Christian East fell to the guns and bigger battalions of Sultan Mehmet II in May 1453. From the ashes of Constantinople, Mehmet built Istanbul, seat of a new Islamic empire that would last through World War I.