The Kefeli Mosque (, meaning "the mosque of the Caffariotes", after the inhabitants of the city of Caffa in Crimea, or also Kefeli Mescidi, where Mescit is the Turkish word for a small mosque) is a former Eastern Orthodox church, later jointly officiated by Roman Catholics and Armenians, and finally converted into a mosque by the Ottomans. The Catholic Church was dedicated to Saint Nicholas. Its date of dedication as an Eastern Orthodox church is unknown, but it is commonly identified with the 9th-century Monastery of Manuel (). The interest of Kefeli Mosque arises because it repurposes the early Christian basilica form during the later Byzantine period. Location The building lies in Istanbul, in the district of Fatih, in the neighborhood of Salmatomruk, on Kasap Sokak, more or less halfway between the mosque of Chora and the mosque of Fethiye. History The origin of this building, which lies on the slope of the sixth hill of Constantinople, is not certain. The tradition says that in the ninth century Manuel the Armenian, a general in the wars against the Saracens during the reign of Emperor Theophilos (r. 829–842), built a monastery converting his house, which lay near the cistern of Aspar. Manuel was the uncle of Empress Theodora, wife of Theophilos, and before retiring to his monastery he was one of the three counselors who assisted her in the regency for her infant son Michael III, following the death of her husband. The Monastery of Manuel was rebuilt by Patriarch Photius, and was restored again by usurper Romanos I Lekapenos (r. 920–944). Emperor Michael VII (r. 1071–1078) retired here after his deposition. All these events show the importance of this monastery in Constantinople. Nevertheless, the attribution of this building to the complex founded by Manuel is far from certain, and has been denied by the newest research. The documented history of the current edifice begins in 1475, shortly after the Fall of Constantinople, when the Ottomans conquered the Genoese colony of Caffa, in Crimea. All the Latin, Greek and Jewish inhabitants who lived in Caffa ("Caffariotes" or, in Turkish, Kefeli) were then deported to Istanbul and relocated to this quarter. The Latins, mainly Genoese, were authorized to use this building as a church together with the Armenians. The church, dedicated to Saint Nicholas, was officiated by the Dominicans, and kept by four Catholic families. Armenians and Catholics had separated altars. This