The Goguryeo–Tang War occurs from 645 to 668 and is initially fought between the Goguryeo kingdom and the Tang empire.

During the course of the war, the two sides ally with various other states.

Exhausted from numerous attacks, Goguryeo and Baekje succumb to a two-front attack by Tang and Silla.Silla will eventually unify the Korean peninsula while the Manchurian areas of Goguryeo will be divided between the Tang and Balhae, which considers itself as the successor to Goguryeo.