Yun Gwan’s Jurchen Campaign and the Nine Forts
Yun Gwan led 170,000 men of the Byeolmuban against the Jurchens and built nine forts in the northeast, but they were handed back after little more than a year.

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In 1107 Goryeo forces under Yun Gwan and O Yeon-chong destroyed some 130 Jurchen villages and built nine forts including Hamju, Yeongju, Ungju, Bokju, Gilju and Gongheomjin. Their location is disputed: the Hamhung plain, the area south of Kilju, or — for Gongheomjin — beyond the Tumen.
The Jurchens asked for the land back, promising tribute and peace, and Goryeo, finding the distant forts hard to hold, returned them in 1109. The Jurchens went on to found Jin in 1115, destroy Liao in 1125 and demand that Goryeo acknowledge Jin as its suzerain.