Eighth Mongol invasion of KoreaKorea
In 1258, Goryeo's King Gojong and one of the retainers of the Choe clan, Kim Injoon, staged a counter-coup and assassinated the head of the Choe family, ending the rule of the Choe family which spanned six decades. Afterwards, the king sued for peace with the Mongols. 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.