It is in Fatih quarter of istanbul. It is Pammakaristos monastery church constructed in Byzantine Period. A grave chapel has been added with the end of the Latin invasion in 13th century. After the conquest, it remained under the control of Christians and used as a women's monastery, in 1455 patriarchate has been moved to this building and the building has been used as patriarchate until 1586. This church has been converted into a mosque by Murat III (1574 - 1595) and the mosque has been named as Fethiye. The northern church is still being used as a mosque. The walls of the additional church are ornamented with the beautiful mosaics of 14th century. After being repaired between the years 1938 - 1940, it has been converted into a unit of Ayasofya Museum.