Heading home, Subutai's forces attacked the allied forces of the Cuman–Kipchaks and the poorly coordinated 80,000 Kievan Rus' troops led by Mstislav the Bold of Halych and Mstislav III of Kiev who went out to stop the Mongols' actions in the area.
Who led the Kievian Rus' troops against Subutai's Mongol army?
Mstislav the Bold of Halych and Mstislav III of Kiev