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. The battle was fought on May 31, 1223 on the banks of the Kalka River in present-day Donetsk Oblast, Ukraine, and ended in a decisive Mongol victory.