Sima Liang (司馬亮) (before 227[1] - 25 July 291[2]), courtesy name Ziyi (子翼), formally Prince Wencheng of Ru'nan (汝南文成王), was briefly a regent during the reign of Emperor Hui during the Western Jin dynasty.
After his nephew Sima Yan (posthumously known as Emperor Wu of Jin) ended Cao Wei and established the Jin dynasty, Sima Liang was created the Prince of Fufeng on 9 February 266[5] and put in charge of the military commands of Qin (秦州, modern eastern Gansu) and Yong (雍州, modern central and northern Shaanxi) provinces.
Despite this, Sima Liang was well respected among the Jin imperial clan for his virtues, including his filial devotion to Princess Dowager Fu.
On 5 October 277,[6] Emperor Wu moved Sima Liang's principality to Ru'nan and put him in charge of the military commands of Yu Province (豫州, modern eastern Henan).
After Empress Jia Nanfeng, Emperor Hui's wife, in conjunction with Emperor Hui's brother Sima Wei the Prince of Chu, overthrew and killed Yang in a coup in April 291, Sima Liang, as the most respected of the imperial princes, was summoned back to the capital Luoyang to serve as regent on 4 May,[7] along with Wei Guan.
To appease those who might have been angry and had overthrown Yang Jun, Sima Liang widely promoted those who participated in the plot, and more than a thousand men were created marquesses.
Empress Jia, who had already resented Wei for having, during Emperor Wu's reign, suggested that he change his heir selection, also wanted more direct control over the government, and therefore resolved to plot a second coup.
His forces thereby surrounded Sima Liang and Wei Guan's mansions, and while both men's subordinates recommended resistance, each declined and was captured.