Hagia Sophia is a Byzantine church located in İznik (Ancient Nicaea), Bursa Province, Turkey. It was built by the Byzantine emperor Justinian I (Justinian the Great) in the 6th century AD. The church is famous for being the place where the Second Council of Nicaea was held in 787 AD. The church was converted into a mosque during the Ottoman era, then into a museum in 1935. In 2011, it was converted again into a mosque.