Three Kingdoms refers to a period of time after the fall of the Han Dynasty in China. It was so named because it was marked by the struggle of three rival kingdoms: the Kingdom of Wei, the Kingdom of Shu and the Kingdom of Wu for control of China. Wei was always the most powerful kingdom and conquered the Shu kingdom in 263. As the Sima clan had effectively wrested control of Wei away from the Cao family, Sima Yan formally seized the throne in 265 and established the Jin Dynasty (265-420). The Kingdom of Wu was later conquered in 280 resulting in the unification of China.