Ankara Treaty of Lausanne (1923), the Turkish nationalists replaced the Ottoman Empire with the Republic of Turkey on 29 October 1923. A few days earlier, Ankara had officially replaced Constantinople as the new Turkish capital city, on 13 October 1923. After Ankara became the capital of the newly founded Republic of Turkey, new development divided the city into an old section, called "Ulus", and a new section, called "Yenişehir". Ancient buildings reflecting Roman, Byzantine, and Ottoman history and narrow winding streets mark the old section. The new section, now centered on Kızılay Square, has the trappings of a more modern city:
Sanjak of Ankara Sanjak of Ankara The Sanjak of Ankara was a second-level province ("sanjak") of the Ottoman Empire. The town of Ankara became part of the Ottoman state in 1361 or perhaps in 1354. It was the first capital ("pasha sanjak") of the Anatolia Eyalet from its formation in the late 14th century until the late 15th century, when it was moved to Kütahya. The "sanjak" of Ankara remained part of Anatolia Eyalet until the latter's dissolution ca. 1841–46, when it became the seat of the new Ankara Eyalet. This was merged into the Bozok Eyalet in 1849, but Ankara remained the