In the mid-to-late 7th century, a series of military conflicts—encompassing the fall of Goguryeo and Baekje under the SillaTang alliance and Tang’s eventual withdrawal from the Korean Peninsula after its confrontation with Silla—came to be designated by various names. At the time, Silla not only regarded itself as having unified the Three Kingdoms by subjugating Baekje and Goguryeo, but also sought to incorporate the Goguryeo population. Accordingly, the term ‘War of the Unification of the Three Kingdoms’ is more appropriate in a contemporaneous sense than ‘Silla’s War to Unify Baekje.’ However, in light of the contemporary meaning of the term ‘unification’ and the international character of the war, the designation warrants reconsideration. One may instead draw attention to appellations such as ‘the Northeast Asian War of the Mid-to-late 7th Century,’ ‘the Manchuria-Korean Peninsula War of the 7th Century,’ or ‘the Three Kingdoms War of the 7th Century.’ Yet such expressions are seldom accompanied by absolute chronological markers, and their excessive length poses limitations to their establishment as universally accepted historical terminology.
This war unfolded in eastern East Asia, where diverse powers took part over an extended period. In this respect, it bears a parallel to the Northern War (1700~1721), an international conflict that took place in Northern Europe in the early 18th century. Therefore, just as the Northern War was so named as a monumental conflict in Northern Europe, this representative war fought in Eastern East Asia during the traditional era may be referred to as the ‘Eastern War.’ Moreover, because the basic framework of the Eastern War—namely, the eastward advance of the Chinese dynasties and its intersection with the dynamics of Manchuria and the Korean Peninsula—can also be discerned in earlier and later contexts, it is necessary to extend the scope of analysis to the period from the late 6th to the late 7th century.