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 during the Three Kingdoms period. It previously existed from 220 to 222 AD as a vassal kingdom nominally under its rival state Cao Wei but declared complete independence in November 222 AD. It was elevated to an empire in May 229 AD after its founding ruler Sun Quan (Emperor Da) declared himself emperor.

The name Wu was derived from the place it was based in—the Jiangnan (Yangtze River Delta) region, which was also historically known as Wu. It was called "Eastern Wu" (東吳; Dōng Wú) or "Sun Wu" (孫吳) by historians to distinguish it from other Chinese historical states with similar names in that region, such as the Wu state of the Spring and Autumn period and the Wuyue kingdom of 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 Sun.

During its existence, Wu's capital was sometimes at Jianye (present-day Nanjing, Jiangsu) and sometimes at Wuchang (武昌; present-day Ezhou, Hubei).