Wu (222–280), commonly known as Dong Wu (Eastern Wu) or Sun Wu, was one of the three major states that competed for supremacy over China in the Three Kingdoms period (220–280). It previously existed from 220–222 as a vassal kingdom nominally under Cao Wei, its rival state, but declared independence from Wei and became a sovereign state in 222. It became an empire in 229 after its founding ruler, Sun Quan, declared himself emperor. ——Wikipedia  @en