Goryeo's royal court had moved in 1232 to Ganghwa Island in the Bay of Gyeonggi after Mongols under Ögedei Khan invaded Goryeo the preceding year as part of a general campaign to conquer China.

The military ruler, Choe U, had insisted on fighting back; the Mongols had ravaged parts of Gyeongsang and Jeolla provinces in the major campaigns of 1231-1232, 1235, 1238.

In 1247, the Mongols had begun the fourth campaign against Goryeo, again demanding the return of the capital to Songdo and the Imperial Family as hostages.

With the death of Güyuk Khan in 1248, however, the Mongols had again withdrawn.

Upon the 1251 ascension of Möngke Khan, the Mongols had again repeated their demands.

Goryeo refuses, and in 1253 the Mongols begin a large campaign.

King Gojong, the twenty-third king of the Goryeo dynasty, finally agrees to move the capital back to the mainland, and sends one of his sons, Prince Angyeonggong, as a hostage.

The Mongols withdraw, but later learn that top Goryeo officials remain on Ganghwa Island, and have punished those who had negotiated with the Mongols.

They renew their campaign.