Battle of the Kalka River
Jebe and Subutai, scouting west during the Khwarazmian campaign, routed an army of Rus princes and Cumans (Polovtsians) on the Kalka River — the first clash between the Mongols and Europe.

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Pursuing Sultan Muhammad II, Jebe and Subutai crossed the Caucasus into the Cuman steppe. At the Cumans’ request the princes of Kyiv, Galicia and other Rus principalities formed a coalition, but on 31 May 1223 on the Kalka they fell for a feigned retreat and were crushed. Captured princes are said to have been crushed beneath the boards on which the Mongols held their victory feast. The Mongols soon turned back east; fourteen years later Batu’s great campaign returned.