This paper aims to examine Goryeo’s diplomatic movements amid East Asia’s international circumstances. Hui-tsung(徽宗), the emperor of the Song(宋) China, was implementing aggressive foreign policies in order to attack the Khitan Liao(遼) and accordingly, mentioned installation three times to Goryeo. Propositions of the first and second installations in 1103 and 1110, respectively, were made when the Khitan’s power was strong and they were the results of recognizing the reality the Khitan was Goryeo’s suzerain state while expressing willingness for installation. The third round of proposition was made in 1123 when the Khitan was rapidly being collapsed by the Jurchen Jin(金), clearly shows that Goyreo would sever relationship with the Khitan Liao and receive asking installation of the Song.
Goryeo rejected the Song’s first round of proposition in 1103 for a realistic reason of the risk of war with the Khitan Liao. However, when the Song presented a relationship of “fictitious installation, which was not real installation”, in 1110 that Goryeo’s king would be treated as an installed king even though Goryeo recognized the Khitan Liao’s suzerainty and the Song officially did not install Goryeo’s King, Goryeo accepted this. The two countries agreed that they would avoid a threat in diplomatic and military terms conscious of the Khitan Liao and maintained ambiguous diplomatic relations. Thereafter as the Jurchens built Jin(金) in 1115, the Song implemented more aggressive policies to militarily suppress the Khitan Liao and in 1123 denied the Khitan Liao’s suzerainty and made more active proposition that the Song would be its suzerain state.
However, Goryeo which watched the growth of the Jurchens from the early 12th century, continuously warned that it was dangerous for the Song to have close diplomatic relations with the Jurchen Jin. Amid such perception of circumstances, Goryeo in 1123 did not accept the Song’s proposition for installation and denied it gracefully, taking an attitude of waiting and seeing circumstances. Resultantly, the Song was placed on the defensive by the Jurchen Jin from 1123 and collapsed in 1127. It shows that Goryeo’s careful diplomatic move was proper.