Mongol Invasions of Korea - Sixth Campaign and Peace

Sixth Campaign and Peace

The Mongols later learned that top Goryeo officials remained on Ganghwa Island, and had punished those who negotiated with the Mongols. Between 1253 and 1258, the Mongols under Jalairtai launched four devastating invasions in the final successful campaign against Korea.

Möngke realized that the hostage was not the blood prince of the Goryeo Dynasty. So Möngke blamed the Goryeo court for deceiving him and killing the family of Lee Hyeong, who was a pro-Mongol Korean general. Möngke' commander Jalairtai devastated much of Goryeo and took 206,800 captives in 1254. Famine and despair forced peasants to surrender to the Mongols. They established a chiliarchy office at Yonghung with local officials. Ordering defectors to build ships, the Mongols began attacking the coastal islands from 1255 onward. In the Liaodong Peninsula, the Mongols eventually massed Korean defectors into a colony of 5,000 households. In 1258, the king and the Choe clan retainer Kim Unjin staged a counter-coup, assassinated the head of the Choe family and sued for peace. When the Goryeo court sent the future king Wonjong as hostage to the Mongol court and promised to return to Kaegyong, the Mongols withdrew from Central Korea.

There were two parties within Goryeo: the literati party, which opposed the war with the Mongols, and the military junta — led by the Choe clan — which pressed for continuing the war. When the dictator Choe was murdered by the literati party, the peace treaty was concluded. The treaty permitted the maintenance of the sovereign power and traditional culture of Goryeo, implying that the Mongols gave up incorporating Goryeo under direct Mongolian control and were content to give Goryeo autonomy, but the king of Goryeo must marry a Mongolian princess and be subordinate to the Mongolian Khans.