Yu Kai 庾楷

Yu Kai 庾楷 (d. 402) was a high official of the late Eastern Jin period 東晉 (317-420).

A native of Yanling 鄢陵, Yingchuan 潁川, he was the grandson of Yu Liang 庾亮 (289-340). Initially appointed as palace attendant (shizhong 侍中), he was promoted to regional inspector (cishi 刺史) of the province of Yuzhou 豫州, stationed at Liyang during the reign of Emperor Xiaowu 晉孝武帝 (r. 372-396).

In 397, Sima Daozi 道子 (364-403), the Prince of Guiji 會稽, fearing the military power held by Wang Gong 王恭 (350-398) and Yin Zhongkan 殷仲堪 (d. 399), assigned Wang Yu 王愉 (d. 404) to Jiangzhou 江州 as a strategic ally. Yu Kai advised against it, warning that Jiangzhou was not a naturally defensible location, but his counsel was ignored.

In 398, Yu Kai allied with Wang Gong and others to rebel. An imperial edict ordered Sima Shangzhi 司馬尚之 (d. 402) to suppress the uprising. Yu Kai, fleeing alone on horseback after his defeat, sought refuge with Huan Xuan 桓玄 (369-404), who appointed him governor (taishou 太守) of Wuchang 武昌.

Fearing Huan Xuan's eventual defeat, Yu Kai secretly conspired with Sima Yuanxian 司馬元顯 (382-402) to attack Huan. However, the plot was discovered, resulting in his arrest.

When Huan Xuan launched an eastward campaign, Liu Laozhi 劉牢之 (d. 402) turned against the court and supported Huan. Upon Huan's arrival in the capital, Yu Kai and Sima Yuanxian were executed.