Sima Liang
In 289, Emperor Wu grew ill, and considered whom to make regent for Crown Prince Zhong. He considered both Yang Jun and his uncle Sima Liang the Prince of Ru'nan, the most respected of the imperial princes. As a result, Yang Jun became fearful of Sima Liang and had him posted to the key city of Xuchang (許昌, in modern Xuchang, Henan). Several other imperial princes were also posted to other key cities in the empire. By 290, Emperor Wu resolved to let Yang and Sima Liang both be regents, but after he wrote his will, the will was seized by Yang Jun, who instead had another will promulgated in which Yang alone was named regent. He died soon after. Crown Prince Zhong ascended the throne as Emperor Hui; Empress Yang was honored as empress dowager, and Yang Jun became regent.