Sambyeolcho Rebellion

The Sambyeolcho Rebellion (1270–1273) was a Korean rebellion against the Goryeo dynasty that happened near the end of the Mongol invasions of Korea. It was suppressed by Goryeo and the Yuan dynasty. After the rebellion, Goryeo became a vassal state of the Yuan dynasty.

Background
From 1231, Goryeo was intermittently invaded by the Mongol Empire. During this time, Goryeo was controlled by a military regime led by the Ch'oe family. In 1232 the government under the nominal king fled to Ganghwa Island, which Mongol horse riders were unable to land on, and resisted the Mongol invasion. Unfortunately because of its fragile foundation, Goryeo faced frequent rebellions. The 1258 rebellion resulted in the establishment of Ssangseong and Dongnyeong Prefectures by the Mongols.

Unlike these rebels, the Sambyeolcho (Three Elite Patrols) were an organ of the military government. They were organized by the Ch'oe family to maintain security. However, unlike the Ch'oe private guards unit (which was to personally protect the family), the Sambyeolcho assumed public functions performed by police and combat forces, effectively replacing the Six Divisions of the military.

In 1258, Ch'oe Ŭi, the fourth dictator of the Ch'oe family, was overthrown by Kim Chun (also known as Kim In-jun) using the Sambyeolcho. Kim Chun took a pro-Mongol policy and sent Crown Prince Wang Chŏng to the Mongol Empire. At the same time, King Gojong and the crown prince approached the Mongols to restore power from Kim Chun.

In 1268, however, Kim Chun was annihilated by the Sambyeolcho under the order of Im Yŏn. The next year, Im Yŏn's attempt to replace King Wonjong was reversed by the crown prince (Chungnyeol) with the help from the Mongol force. In 1270, Im Yŏn's successor Im Yu-mu was killed by the pro-Mongol faction using the Sambyeolcho. It marked the end of the military regime.

Anti-Mongol struggle
By the order of the Mongol court, Wonjong moved the capital from Ganghwa Island to Kaesŏng. Regaining power from military officials with the support of the Mongols, the king decided to abolish the Sambyeolcho. Resentful of the peace terms worked out with the Mongols, the Sambyeolcho, led by Pae Chung-son, revolted against the government. Systematically blocking passage between Gangwha and the mainland, they brought nearby islands and coastal regions under their domain. Wang On, a royal kinsman was proclaimed king of the maritime kingdom. They gave up Ganghwa Island and fled to Jindo Island in the southwest.

Although the Sambyeolcho raided the coastlines of Jeolla Province, the southwestern province, Jindo Island started to face food shortages in January 1271. In February the court of Kublai Khan's Yuan dynasty called for the Sambyeolcho's surrender. In response, its leader, Pae Chung-son, asked Kublai Khan to secure Jeolla Province and put it under the direct rule of the empire, just as preceding rebels had. But his request was never fulfilled.

In April, the Yuan court decided to crush the rebels. It only took a month for Jindo Island to fall to a combined Goryeo and Yuan army. The puppet king was killed and the survivors, led by Kim T'ong-jŏng, fled to Jeju Island. The rebels captured the island and banished the king of Tamna in November 1270.

The Sambyeolcho laid low until the end of 1271. During that time, they sought help from Japanese Kamakura Shogunate. They regained their strength to some degree the following year. They repeatedly looted the Korean coast. A combined Goryeo-Yuan assault began in February 1272, and crushed the rebels in April. Thereafter, the Yuan dynasty directly controlled Tamna until 1294.