Chagatai[a] , also known as Turki, Eastern Turkic, or Chagatai Turkic , is an extinct Turkic literary language that was once widely spoken across Central Asia and remained the shared literary language there until the early 20th century. It was used across a wide geographic area including parts of modern-day Uzbekistan, Xinjiang, Kazakhstan, and Kyrgyzstan. Literary Chagatai is the predecessor of the modern Karluk branch of Turkic languages, which include Uzbek and Uyghur. Turkmen, which is not within the Karluk branch but in the Oghuz branch of Turkic languages, was nonetheless heavily influenced by Chagatai for centuries.