The Battle of Chakirmaut in 1204 shattered the forces of the Merkit-Naimans alliance and the survivors fled into southern Western Siberia.
When Jochi, the son of Genghis, led an expedition into Siberia to subjugate what the Mongols called the "Forest Peoples", he encountered the remnant armies of the Merkits and Naimans at the Irtysh and soundly defeated them, shattering the alliance.
[4] The Merkit and Naimans who survived the battles against the Mongols fled into Western Siberia, where they eventually gathered at the Irtysh.
[8] Temujin's victory against the alliance consolidated his control of the Mongol and Turkic tribes in the region.
The presence of the Merkit and Naimans there posed a threat to the new empire, and Genghis did not give them long to foment opposition.
[8] The Oirat leader Qutuqa Beki, who previously had opposed Genghis, met Jochi's army and submitted to the empire, giving it 10,000 soldiers.
[16][17] Qudu, the surviving son of Toqto'a, escaped to what is now northern Kazakhstan, but was pursued and defeated by Subutai and Jebe.