Chronologically, at the beginning it was a church built by Saint Theodius by order of Byzantine Emperor Justinious in 534, then in 11th century it was rebuilt by mother- in- law of Emperor Alexious, Maria Doukaina. But,devastated during Latin Invasion between (1204-1261), church was repaired by creative architect Theodoros Metokhites in 14th century. He made use of the Renaissance architecture style by adding the narthex and the paracclesion. After Ottoman Sultan Fatih Sultan Mehmet's conquest of Istanbul, that repaired church was turned into a mosque by the visier Ali Hadım Pasha like Hagia Sophia church. At last it is used as a museum now.