In V. Gordlevskij’s words, “In order to understand the history of Turkic peoples it is necessary to study the Mongols”. But the other way round is also true: in order to understand the history of the Mongols a knowledge of Turkic history is indispensable. The present article tries to elucidate some aspects of the Turkic impact on Mongol history by investigating the role of the Turks (Uighurs, Kipchaks and Kanglis) who stood in the service of the Yuan, Mongol dynasty of China in the 13th–14th centuries.