The relationship between the Ungjin Commandery and Shilla was examined through the Mt. Chuiri Covenant in 665, which contained the bond the commandery and the kingdom forged through marriage. However, Park Do-yu, the governor of Hansan-ju who was supp...
The relationship between the Ungjin Commandery and Shilla was examined through the Mt. Chuiri Covenant in 665, which contained the bond the commandery and the kingdom forged through marriage. However, Park Do-yu, the governor of Hansan-ju who was supposed to get married to form a bond with the kingdom broke the covenant, which destroyed the budding relationship between the commandery and the kingdom. Park Do-yu`s betrayal was significant in history. The fact that Park Do-yu, who was supposed to get married to a woman from Shilla or Tang based on the Mt. Chuiri Covenant, was coaxed by the Ungjin Commandery to betray the kingdom meant the end of the covenant. The event is recorded only in "answer for the writing of Seol In-gui." Furthermore, the annals of Shilla in 『Samguksagi』 contains Su-se`s betrayal in 670 not Park Do-yu`s betrayal. The two events, however, turned out to be identical. Therefore, it is assumed that Park Do-yu`s or Su-se`s betrayal occurred around 670. It seems that the operation Seol Oh-yu from Shilla and Go Yeon-mu from Goguryeo carried out together between March and April 670 caused Park Do-yu to break the covenant. As a result of the operation, Park Do-yu, who was close to Tang and married to a Baekje woman from the Ungjin Commandery, was forced to choose between Tang and Shilla, It is presumed that having witnessed Baekje and Gorguryeo being defeated by Shilla, Park Do-yu was coaxed by the Ungjin Commandery to choose Tang. Ungjin Commandery and Silla exchanged Yegun, a person of Ungjin Commandery, and Kim Yu-don, one of Silla, as hostages in July, 670 in order to solve the Park Do-yu betrayal.