Emperor Wu of Jin, (236 – May 17, 290), personal name Sima Yan, style name Anshi, is the grandson of Sima Yi and son of Sima Zhao.

He becomes the first emperor of the Jin Dynasty (265-420) after forcing Cao Huan, last ruler of the state of Cao Wei, to abdicate to him.

He reignsfrom 265 to 290, and after conquering the state of Eastern Wu in 280, is the emperor of a unified China.

Emperor Wu is known for his extravagance and sensuality, especially after the unification of China; legends boast of his incredible potency among his ten thousand concubines.

Emperor Wu is commonly viewed as a generous and kind, but also wasteful, ruler.

His generosity and kindness undermine his rule, as he becomes overly tolerant of the noble families' corruption and wastefulness, which drains the people's resources.

Further, when Emperor Wu establishes the Jin Dynasty, he is concerned about his regime's stability, and, believing that the predecessor state, Cao Wei, had been doomed by its failures to empower the princes of the imperial clan, he greatly empowers his uncles, his cousins, and his sons with authority including high military ranking.

This ironically leads to the destabilization of the Jin Dynasty, as the princes engage in an internecine struggle known as the War of the Eight Princes soon after his death, and then the Wu Hu uprisings that nearly destroy the Jin Dynasty and force its relocation to the region south of the Huai River.