In 376 BC, Han, Wei, and Zhao deposed Duke Jing of Jin.
The following year, after two unsuccessful invasions, Han annexed the Zheng state.
According to Zizhi Tongjian, while Marquess Ai appointed Han Xialei (韓俠累) to be prime minister, he had closer relations with Yan Sui (嚴遂).
In 374 BC, Yan Sui plotted to assassinate Han Xialei at the court.
[1] However, the Records of the Grand Historian tells a different story: Marquess Ai was murdered by Han Xialei and Yan Sui, and it was not an accident.