Mstislav went to war against the Mongols of Genghis Khan in 1223 and was defeated at the Battle of the Kalka River by the warlord Subutai, after which he was executed.
Mstislav went to war against the Mongols of Genghis Khan in 1223. Mstislav was defeated at the Battle of the Kalka River by the warlord Subutai. He was executed after the warlord Subutai.