During the first Mongol invasion of Russia (Kievan Rus), an army led by Jebei and Subutai defeated an alliance of Russian princes and the Cuman tribal group along the Kalka River (probably the modern Kalchik River in southeastern Ukraine, which flows into the Sea of Azov) on May 31, 1223. The victory, part of a prolonged raiding campaign, devastated the Russian princes’ armies and demonstrated the raw power of the Mongol cavalry. It was the first significant Mongol military engagement in Europe.
Granted permission to do so by Genghis Khan after their victories over the Khwarazmian Empire, in 1221 Mongolian generals Jebei and Subutai led an army of 20,000 on a raid through Azerbaijan, into Georgia, and along the Caspian Sea into Russia. The raiders defeated an alliance of Turkic tribes from the steppes, including the Alans, Cherkes, and Kipchaks, then wiped out two armies of Cumans (another Turkish tribe); the few Cuman survivors appealed for help to the princes of Kievan Rus, a state already in decline.
These princes—including Mstislav III of Kiev, Mstislav of Galich, and Yuri II of Vladimir—raised an army of 30,000 men in alliance with the Cumans and, by advancing on three separate fronts, attempted to encircle the Mongol force on the banks of the Dnieper River. The Mongols made a feigned retreat to the east, leaving a rear guard of 1,000 men to fight under the command of Hamabek; this rear guard was wiped out by an army commanded by Mstislav of Galich, who then pursued the main Mongol force.
After nine days in retreat, the Mongols turned to engage Mstislav on the banks of the Kalka River. They attacked the Russian army head-on and on the flanks, with typical ferocity. The Cumans fled, causing disarray in the Russian ranks, and the Mongols swept through the gap this created. Afterward Jebei and Subutai forced the surrender of the Russian contingent under Mstislav of Kiev and pursued the remnants of Mstislav of Galich’s army, before giving up the chase and allowing him to escape.
Although unquestionably the victors at Kalka, the Mongols did not invade Rus again for another 15 years. The deaths of so many princes and their soldiers caused instability in the Kievan principalities, and the Cumans aligned themselves afterward with the stronger Hungarian kingdom.
Losses: Russian, 20,000 of 30,000; Mongol, very few.