Eastern Wu
Wu (Chinese: 吳; pinyin: Wú; Middle Chinese *ŋuo < Eastern Han Chinese: *ŋuɑ), known in historiography as Eastern Wu or Sun Wu, was a dynastic state of China and one of the three major states that competed for supremacy over China in the Three Kingdoms period. It previously existed from 220 to 222 as a vassal kingdom nominally under Cao Wei, its rival state, but declared complete independence from Cao Wei in November 222. It was elevated to an empire in May 229 after its founding ruler, Sun Quan (Emperor Da), declared himself emperor. Its name was derived from the place it was based in—the Jiangnan (Yangtze River Delta) region, which was also historically known as "Wu". It was referred to as "Dong Wu" ("Eastern Wu") or "Sun Wu" by historians to distinguish it from other Chinese historical states with similar names which were also located in that region, such as the Wu state in the Spring and Autumn period and the Wuyue kingdom in the Five Dynasties and Ten Kingdoms period. It was called "Eastern Wu" because it occupied most of eastern China in the Three Kingdoms period, and "Sun Wu" because the family name of its rulers was