Byzantine Emperors entered Hagia Sophia through this hallway, nicknamed the Vestibule of the Guards because the Imperial soldiers hung out here while their ruler attended church services. The mural above the vestibule door dates back to the 11th century and shows Mary and Jesus being presented with gifts from two important Byzantine Emperors. Constantine (right) offers the city of Istanbul, and Justinian (left) serves up Hagia Sophia itself, his greatest claim to fame.