Goguryeo's ally within the southwest, Baekje, fell on the Silla?�Tang alliance in 660; the victorious allies continued their assault on Goguryeo for another eight several years. In the meantime, in 666 (nevertheless dates vary from 664??66), Yeon Gaesomun died and civil war ensued among the his 3 sons. Silla?�Tang at https://trentoni3uh1.alltdesign.com/the-single-best-strategy-to-use-for-goguryeo-room-salon-46797217