Battle of the Kalka River
The Battle of the Kalka River was fought between the Mongol Empire, whose armies were led by Jebe and Subutai, and a coalition of several Rus' principalities, including Kiev and Galicia-Volhynia, and the Cumans under Köten. They were under the joint command of Mstislav the Bold and Mstislav III of Kiev.
Source: Wikipedia — Battle of the Kalka River (CC BY-SA 4.0)