Mehmed II begins his siege of Constantinople. The city falls on May 29 and is renamed Istanbul.

Mehmed II, commonly known as Mehmed the Conqueror, was twice the sultan of the Ottoman Empire from August 1444 to September 1446 and then later from February 1451 to May 1481.

The Fall of Constantinople, also known as the Conquest of Constantinople, was the capture of the capital of the Byzantine Empire by the Ottoman Empire. The city was captured on 29 May 1453 as part of the culmination of a 55-day siege which had begun on 6 April.

May 29 is the 149th day of the year in the Gregorian calendar; 216 days remain until the end of the year.

Istanbul is the largest city in Turkey, constituting the country's economic, cultural, and historical heart. With a population over 15 million, it is home to 18% of the population of Turkey. Istanbul is among the largest cities in Europe and in the world by population. It is a city on two continents; about two-thirds of its population live in Europe and the rest in Asia. Istanbul straddles the Bosphorus—one of the world's busiest waterways—in northwestern Turkey, between the Sea of Marmara and the Black Sea. Its area of 5,461 square kilometers (2,109 sq mi) is coterminous with Istanbul Province.

April 6 is the 96th day of the year in the Gregorian calendar; 269 days remain until the end of the year.