Edirne, historically known as Adrianople, is a city in the northwestern Turkish province of Edirne in the region of East Thrace, close to Turkey's borders with Greece and Bulgaria. Edirne served as the third capital city of the Ottoman Empire from 1369 to 1453, before Constantinople (present-day Istanbul) became the empire's fourth and final capital between 1453 and 1922. The city's estimated population in 2014 was 165,979.