. . . . "1220\u20131224 invasion of the Cumans" . . "Unknown" . "battle of the Kalka River" . "Battle of the Kalka River" . "Cumans" . . . . . "20,000\u201323,000 men" . "Battle of Kalka River" . . "battle on the river Kalka" . "Principality of Chernigov" . "8,000\u201380,000" . . "Mongol Empire" . "at the Kalka River" . . "they met the main Mongol force" . "Kalka River" . "Principality of Smolensk" . "battle of Kalka" . . . . . . . . . "1223-05-31" . "Mongolvictory" . . "Kalka" . . . . . . . . . "Principality of Galicia-Volhynia" . "battle" . . "Battle of the Kalka River" . "1223 battle at Kalka River" . . . . . . "they defeated a joint Rus\u2019-Cuman army at the river Kalka" . "Principality of Kiev" . "Brodnici" . "Kievan Rus'" . . .