quality:correction
Return to Constantinople (1453–1478)

After conquering Constantinople, when Mehmed II finally entered the city through what is now known as the Topkapi Gate, he immediately rode his horse to the Hagia Sophia, where he ordered the building to be protected. He ordered that an imam meet him there in order to chant the Muslim Creed: "I testify that there is no god but Allah. I testify that Muhammad is the messenger of Allah." The Orthodox cathedral was transformed into a Muslim mosque through a charitable trust, solidifying Islamic rule in Constantinople.

Mehmed's main concern with Constantinople was with rebuilding the city's defenses and repopulation. Building projects were commenced immediately after the conquest, which included the repair of the walls, construction of the citadel, a remarkable hospital with students and medical staff, a large cultural complex, two sets of barracks for the janissaries, a tophane gun foundry outside Galata, and a new palace. To encourage the return of the Greeks and the Genoese who had fled from Galata, the trading quarter of the city, he returned their houses and provided them with guarantees of safety. Mehmed issued orders across his empire that Muslims, Christians, and Jews should resettle in the city, demanding that five thousand households needed to be transferred to Constantinople by September. From all over the Islamic empire, prisoners of war and deported people were sent to the city; these people were called "Sürgün" in Turkish (Greek: σουργούνιδες sourgounides; "immigrants").

Mehmed restored the Ecumenical Orthodox Patriarchate (6 January 1454), monk Gennadios being appointed as the first Orthodox Patriarch, and established a Jewish Grand Rabbinate (Ḥakham Bashi) and the prestigious Armenian Patriarchate of Constantinople in the capital, as part of the millet system. In addition, he founded, and encouraged his viziers to found, a number of Muslim institutions and commercial installations in the main districts of Constantinople, such as the Rum Mehmed Pasha Mosque built by the Grand Vizier Rum Mehmed Pasha. From these nuclei, the metropolis developed rapidly. According to a survey carried out in 1478, there were then in Constantinople and neighboring Galata 16,324 households, 3,927 shops, and an estimated population of 80,000. The population was about 60% Muslim, 20% Christian, and 10% Jewish.

By the end of his reign, Mehmed's ambitious rebuilding program had changed the city into a thriving imperial capital. According to the contemporary Ottoman historian Neşri, "Sultan Mehmed created all of Istanbul". Fifty years later, Constantinople had again become the largest city in Europe.

Two centuries later, the well-known Ottoman itinerant Evliya Çelebi gave a list of groups introduced into the city with their respective origins. Even today, many quarters of Istanbul, such as Aksaray and Çarşamba, bear the names of the places of origin of their inhabitants. However, many people escaped again from the city, and there were several outbreaks of plague, so that in 1459 Mehmed allowed the deported Greeks to come back to the city. This measure apparently had no great success, since French voyager Pierre Gilles wrote in the middle of the 16th century that the Greek population of Constantinople was unable to name any of the ancient Byzantine churches that had been transformed into mosques or abandoned. This shows that the population substitution had been total.