Following the Mongol occupation of Russia, many Cuman-Kipchak tribes fled the country and travelled west. One such tribe was that led by Kotjan Kahn, which headed to Hungary. There, they were offered asylum if they converted to Christianity. They did so and allied themselves with the Hungarian king, Béla IV, vowing to fight the Mongols, who were preparing to invade. However, in 1241, worried that Béla was using the Cumans to solidify his hold on power, Hungarian nobles murdered Kotjan. This infuriated the tribe, who immediately left Hungary, heading towards the Balkans, and destroying every village in their path. En route, they are attacked by a Mongol force led by Subutai, and many are killed, leaving the path open for the Mongols to invade Hungary and continue with the occupation of Europe.