Istanbul Fatih district, which was named after Sultan Mehmed the Conqueror (Turkish: "Fatih Sultan Mehmed"), corresponds to what was, until the Ottoman conquest in 1453, the whole of the city of Constantinople (today is the capital district and called the "historic peninsula" of Istanbul) on the southern shore of the Golden Horn, across the medieval Genoese citadel of Galata on the northern shore. The Genoese fortifications in Galata were largely demolished in the 19th century, leaving only the Galata Tower, to make way for the northward expansion of the city. Galata (Karaköy) is today a quarter within the Beyoğlu (Pera) district,
Galata was built in place of a 6th-century Byzantine church in Galata. This chapel was significantly enlarged in 1325 by the Dominican friars, who officially renamed it as the Church of San Domenico, but local residents continued to use the original denomination of San Paolo. In 1407, Pope Gregory XII, in order to ensure the maintenance of the church, conceded indulgences to the visitors of the Monastery of San Paolo in Galata. The building is known today as the "Arap Camii" (Arab Mosque) because a few years after its conversion into a mosque (between 1475 and 1478) under the Ottoman Sultan