JB119239 Emperor Leo the Wise kneeling to Christ Pantocrator (mosaic) by Byzantine, (10th century); Hagia Sophia, Istanbul, Turkey; (add.info.: Mosaic from the tympanum of the Imperial Gate, of Leo VI kneeling before Christ Pantocrator, with roundels of the Virgin Mary and the Archangel Gabriel above. Hagia Sophia was built in 537 as a Greek Orthodox Cathedral and converted to a mosque when the Ottoman Turks conquered Constantinople in 1453. Since 1935 it has been a museum (Unesco World Heritage List, 1985).); 穢 John Bethell; out of copyright.