structural:summarization
Korea

In 1224, a Mongol envoy was killed in obscure circumstances and Korea stopped paying tribute. Ögedei dispatched Saritai qorchi to subdue Korea and avenge the dead envoy in 1231. Thus, Mongol armies began to invade Korea in order to subdue the kingdom. The Goryeo King temporarily submitted and agreed to accept Mongol overseers. When they withdrew for the summer, however, Ch'oe U moved the capital from Kaesong to Ganghwa Island. Saritai was hit with a stray arrow and died as he campaigned against them.

Ögedei announced plans for the conquest of the Koreans, the Southern Song, the Kipchaks and their European allies, all of whom killed Mongol envoys, at the kurultai in Mongolia in 1234. Ögedei appointed Danqu commander of the Mongol army and made Bog Wong, a defected Korean general, governor of 40 cities with their subjects. When the court of Goryeo sued for peace in 1238, Ögedei demanded that the king of Goryeo appear before him in person. The Goryeo king finally sent his relative Yeong Nong-gun Sung with ten noble boys to Mongolia as hostages, temporarily ending the war in 1241.