Yun Gwan Yun Gwan ( 12 July 1040 - 15 June 1111 ) was a general of Goryeo who was known for training a seventeen - thousand man army and leading it to victory against the Jurchens tribes . Background . Yun Gwan is from the Papyeong Yun ( many of this clan also uses , the PapPyong " Yoon " the phonetic spelling for the clan name ) . His military career began when he passed the state civil examination . According to the Yun family history book , Yun Gwan was born on July 12 , 1040 and died on June 15 , 1111 . ( Goryeosa also mentions he died on June 15 , 1111 . ) Koreans dedicated a large statue of General Yun Gwan in a small park near the Seoul Central Train Station which describes his contribution to Korean national history . The Jurchen Expedition . Jurchen tribes lived to the north of Goryeo . The Jurchens always rendered tribute to the Kings of Goryeo , but the Jurchen tribes grew strong , and were soon united under Wanyan . They began to violate the Goryeo - Jurchen borders , and eventually invaded Goryeo . Goryeo , however , did not have a powerful army at that time , due in part to a century of peaceful existence . With the invasion of the Jurchen , King Sukjong ordered all available soldiers into battle , but this ended in defeat . General Yun Gwan convinced the Jurchen leaders to pull their troops back , and this ended the invasion of the Jurchen . Victory over the Jurchen . After experiencing the invasion by the Jurchen , Yun Gwan realized that Goryeo lacked efficient cavalry units , and requested permission from King Sukjong to train and reorganize the current Goryeo military into a professional army that would contain decent and well - trained cavalry units . Finally , in 1107 , General Yun led the newly formed Goryeo army , a force of approximately 17 thousand men called Byeolmuban , and attacked the Jurchens tribes . Though the war lasted for several years , the Jurchen were ultimately defeated , and surrendered to Yun Gwan . To mark the victory , General Yun built nine fortresses to the northeast of the Goryeo - Jurchen borders ( Hangul : 동북 9성 , Hanja : 東北 九城 ) . In 1108 , however , General Yun was given orders to withdraw his troops by Goryeo ' s new ruler , King Yejong . Due to manipulation and court - intrigue from opposing factions , he was discharged from his post . Along with this , the opposing factions fought to make sure that the new nine fortresses were returned to the Jurchens . Soon after , Yun Gwan was released from his prison in 1110 , and was offered a chance to return to his duties as general , but he gently refused and returned to his hometown . A year later , in 1111 , Yun Gwan died . Aftermath . After the death of Yun Gwan , the Jurchen destroyed the Liao dynasty , and established the Jin Dynasty . With the rise of the Jin , Goryeo was no longer able to trade with the Song Dynasty or any of the other neighboring nations , and became isolated , which contributed to the weakening of the kingdom . Dispute . The extent of Yun Gwan ' s military campaigns has been in dispute for centuries . While the general belief is that his nine fortresses were built in present - day Hamheung in North Korea , a number of historical sources seem to indicate that Yun took parts of Manchuria for Goryeo , temporarily claiming the land of Goryeo ' s ancestors , Goguryeo . Family Feud . Because of Korea ' s tragic history of wars and invasions , the location of Yun Gwan ' s tomb was lost until the 18th century . Yun Gwan ' s tomb was located near another tomb belonging to the Sim clan . Because of this a family feud erupted between the Yuns and Sims lasting 300 years .