Diplomatic Relations Between Goguryeo(高句麗) and Rouran(柔然) in the 5th Century and the ‘Mongolian Steppe Route(蒙古草原路)’

In the 5th century, Goguryeo engaged in diplomatic negotiations with various groups. Among these, the interactions with the Rouran(柔然), who were active in the Mongolian Steppe, are particularly noteworthy. This article examines the background and aspects of the 5th-century diplomatic relations between Goguryeo and Rouran, the development of the Jiduwu(地豆于) division incident in 479, which provides insight into the actual state of their relationship, and the effects and significance of securing the Mongolian Steppe Route(蒙古草原路). Goguryeo and Rouran initially made contact in the early 5th century through the intermediary of Northern Yan. However, their diplomatic relations became visible only after the mid-430s, influenced by Northern Wei's efforts to unify northern China. Both Goguryeo and Rouran, bordering Northern Wei, sought to mitigate the threats they faced and secure allied forces. Their mutual interest grew, and their relations gradually strengthened. A concrete example of the previously circumstantial evidence of Goguryeo and Rouran's negotiations is the division of the Jiduwu region in 479. Although there are various opinions regarding whether this event was actually carried out, this article argues that, based on an analysis of the international situation in the late 470s and the movements of surrounding powers such as the Khitan(契丹), the division of Jiduwu by Goguryeo and Rouran was indeed executed. Through this, Goguryeo and Rouran were able to secure the so-called Mongolian Steppe Route that connected the two powers. Goguryeo was able to control or restrict the activities of various powers in Manchuria, including the Khitan. Furthermore, the Mongolian Steppe Route, connected to Liaodong, developed into a network that linked Goguryeo with various steppe forces. This steppe network enabled the steppe groups to receive supplies of essential goods like food and iron. Meanwhile, Goguryeo secured goods from the steppe, which were either consumed domestically or used for trade with third parties. The establishment of the steppe network did not merely connect Goguryeo with the steppe forces but also laid the foundation for creating a broader regional network by linking it with another network connected to Liaodong.