Old Uyghur language

Old Uyghur was the Turkic language of the Uyghur Kingdom of Qocho and the Gansu Uyghurs from the 9th to the 14th centuries. Written mainly in the Old Uyghur script, derived from Sogdian, it was the language of a large Buddhist, Manichaean and Christian literature, much of it translated from Sanskrit, Tocharian, Chinese and Sogdian. Its script later became the basis of the Mongolian alphabet.