The Old Uyghur alphabet was used for writing the Old Uyghur language, a variety of Old Turkic spoken in Turfan (also referred to as Turpan) and Gansu that is the ancestor of the modern Western Yugur language. The term "Old Uyghur" used for this alphabet is misleading because Qocho, the Tocharian-Uyghur kingdom created in 843, originally used the Old Turkic alphabet. The Uyghur adopted this "Old Uyghur" script from local inhabitants when they migrated into Turfan after 840. It was an adaptation of the Aramaic alphabet used for texts with Buddhist, Manichaean and Christian content for 700–800 years in Turpan. The last known manuscripts are dated to the 18th century. This was the prototype for the Mongolian and Manchu alphabets. The Old Uyghur alphabet was brought to Mongolia by Tata-tonga.