The Ayasofya (Hagia Sophia) is a former Orthodox patriarchal basilica, later a mosque, and now a museum. From the date of its dedication in 360 until 1453, it served as the Greek Patriarchal cathedral of Constantinople, except between 1204 and 1261 when it was converted to a Roman Catholic cathedral. The building was a mosque from 1453 until 1931, when it was secularized. It was opened as a museum in 1935.
The current building was originally constructed as a church between 532 and 537 on the orders of the Byzantine Emperor Justinian and was the third Church of the Holy Wisdom to occupy the site, the previous two having both been destroyed by rioters. Famous in particular for its massive dome, it is considered the epitome of Byzantine architecture. It was the largest cathedral in the world for nearly a thousand years, until Seville Cathedral was completed in 1520.
The two large alabaster urns located on two sides of the nave were transported from the ruins of Pergamon.