Boksin as a diplomatic representative of Baekje was dispatched to Tang in 627 for a mission making a favorable international environment for expansion policy to Silla with which King Mu of Baekje actively had pursued. But King Taizong of Tang sent to Boksin a letter in which he deprecated a military act of Baekje, so Boksin became left the political stage with taking the responsibility for a diplomatic failure.
Ironically, it was because of a Baekje`s misfortune that Boksin who had been forgotten for over 30 years rose to main power. He took the lead at once in Baekje`s forces of the revival movement which have been in the crunch, and built foundation which could fight against Silla and Tang by establishing Juryu-fortress(Buan) centered system. Then, he spread the movement to all the Baekje`s area with winning both battles of Duryangi-fortress and Gosabi-fortress in April 661.
But, on his way Dochim, companion of the movement, made effort to withdraw Tang`s troops through a negotiation, the forces be faced with crisis such as Ongsan-fortress, a major hotspot for defense, were taken to Silla, a military alliance with Tang, in the end of september 661 and some areas surrendered to it, etc. Boksin made it as an opportunity, removed Dochim and was able to change the political situation. Then he caught the political power entirely after he subdued Pungchang who came back to Baekje in December 661.
From then, Boksin took the lead in all forces of the movement. But he lost again the main fortresses one after another owing to attacks of Silla and Tang forces resumed from July 662. Besides, though he tried to transfer capital to Pi-fortress in December 662 for changing this situation, this plan failed because of the loss of the `Important Places,` e.g. four southern provinces and Dukan-fortress, in February 663. In the end, Boksin driven into a corner was killed by the coup of King Pung.