Sima Wei (司馬瑋) (271[1] – 26 July 291[2]), courtesy nameYandu (彥度), formally Prince Yin of Chu (楚隱王), was an imperial prince during the Western Jin dynasty and was the second of the eight princes commonly associated with the War of the Eight Princes.
^According to Sima Wei's biography in Book of Jin, he was 21 (by East Asian reckoning) when he died. (诏以玮矫制害二公父子，又欲诛灭朝臣，谋图不轨，遂斩之，时年二十一。) Jin Shu, vol.59. Thus by calculation, his birth year should be 271.
^According to Sima Zhong's biography in the Book of Jin, Sima Wei was killed on the yichou day in the 6th month of the 1st year of the Yongping era of Emperor Hui's reign. This corresponds to 26 Jul 291 in the Gregorian calendar. [(永平元年)六月...乙丑，以瑋擅害亮、瓘，殺之] Book of Jin, vol. 4