Emperor Jin Mindi 晉愍帝 (270-317, r. 313-316), personal name Sima Ye 司馬鄴, courtesy name Yanqi 彥旗, was the last emperor of the Western Jin dynasty 西晉 (265-316). He was a nephew of his predecessor, Emperor Huai 晉懷帝 (r. 306-312), and a son of Sima Yan 司馬晏 (281-311), Prince Xiao of Wu 吳孝王.
In his childhood he inherited the title of Prince of Qin 秦王, which was before borne by Sima Jian 司馬柬 (262-291), Prince Xian of Qin 秦獻王. In 308, Sima Ye was appointed cavalier attendant-in-ordinary (sanji changshi 散騎常侍) and General Supporter-of-the-Army (fujun jiangjun 撫軍將軍).
When the imperial capital Luoyang 洛陽 (today in Henan) and Emperor Huai fell into the hands of the Xiongnu 匈奴 leader Liu Yao 劉曜 (d. 329), Sima Ye fled to Xingyang 滎陽 (today in Henan). Somewhat later he moved to Chang'an 長安 (today's Xi'an 西安, Shaanxi), where he was received by loyal officials like Jia Pi 賈匹, regional inspector (cishi 刺史) of the province of Yongzhou 雍州. In 312, he was formally appointed Heir Apparent (huang taizi 皇太子). A year later, the captive Emperor Huai was killed by Liu Yao in Pingyang 平陽 (close to present-day Linfen 臨汾, Shanxi), and Sima Ye was enthroned as the emperor of Jin, but he was virtually residing in exile in Chang'an.
He chose the reign motto Jianxing 建興 "Promoting Prosperity" and appointed Qu Yun 麴允 (d. 316) overseer of the imperial secretaries (lu shangshu shi 錄尚書事), and made Suo Lin 索綝 (d. 316) Defender-in-chief (taiwei 太尉). Both persons were this his closest advisors in political matters. At that time, Chang'an had a population of barely 100 households, and the court disposed of no more than 4 carts.
Shortly later, Liu Yao invaded the Guanzhong region 關中 and attacked Chang'an, but Suo Lin was able to repel him. In 316, Liu Yao attacked once more and was nearly able to starve the city of Chang'an. Sima Ye had no chance but to open the gates to the besiegers. Riding a cart drawn by goats, and without being clothed in state robes (historiographers say, he was naked), Sima Ye surrendered to Liu Yao. The victor gave him the title of Marquis of Huai'an 懷安侯, and allowed him to reside in Pingyang.
A year later, Liu Cong 劉聰 (r. 309-317), who called himself emperor of the (Northern) Han dynasty 北漢 (304-317, later renamed and better known as Former Zhao 前趙, 317-329), ordered Sima Ye, who served the Han "emperor" in the function of Grand Master of Splendid Happiness (guanglu dafu 光祿大夫), to accompany him during a hunting expedition, but only gave him the functions of a subordinate, like bearing halberds in the advance party or preparing the drinking vessels and holding the umbrella during a banquet. When Sima Ye's former ministers began to weep because of this humiliating treatment, Liu Cong was enraged and had Sima Ye killed.