War of the Eight Princes
Sima Yue was the son of Sima Tai (司馬泰) the Prince of Gaomi, who was the son of Sima Yi's brother Sima Kui (司馬馗), making him cousin of Jin's founding emperor Emperor Wu. In 291, early in Emperor Hui's reign, he was created the Prince of Donghai. During the early parts of the War of the Eight Princes, he held a number of offices in the capital Luoyang.