Kefeli Mosque
Istanbul, Turkey
The Kefeli Mosque (Kefeli Câmîi, 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 (ὴ ῦ). The interest of Kefeli Mosque arises because it repurposes the early Christian basilica form during the later Byzantine period.
Mosque data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).