First Mongol invasion of Poland: Mongols overwhelm Polish armies in Kraków in the Battle of Chmielnik and plunder the city.
The Battle of Chmielnik occurred on 18 March 1241 during the Mongol invasion of Poland. It ended in the defeat of the Polish armies of Sandomierz and Krakw provinces. The Mongols were able to move unimpeded, and plunder the abandoned city of Krakw.
The Mongol Invasion of Poland from late 1240 to 1241 culminated in the Battle of Legnica, where the Mongols defeated an alliance which included forces from fragmented Poland and their allies, led by Henry II the Pious, the Duke of Silesia. The first invasion's intention was to secure the flank of the main Mongolian army attacking the Kingdom of Hungary. The Mongols neutralized any potential help to King Béla IV being provided by the Poles or any military orders.