Regicide plagued imperial China throughout its history from 1046 BCE to 1911 CE. Of the 1,948 rulers of 448 states or polities that covered the area of what we now know as China, 35.7% died unnaturally, implying a regicide rate of 2,899.8 deaths per 100,000 ruler-years. With so many rulers either killed or forced to commit suicide, only 1.4% of the regicides were the result of peasant uprisings, with the rest committed by the ruler’s relatives and trusted ministers or invading armies. Aristotle once hypothesized that in an autocracy, both the inner court and the masses are motivated to kill its ruler, but the literature has not shown which of the two poses a bigger threat to the ruler’s life. We demonstrate that, at least in Chinese history, members of the court were far more likely to be perpetrators of regicide. Still, not all dynasties suffered regicide to the same extent because institutional reforms in the Tang and later dynasties altered the political calculus. The probability of regicide was lower for rulers who appointed a successor but higher for those who relied on a regency of ministers at the time of ascension or whose predecessor died unnaturally. Succession uncertainty was a clear threat to the ruler’s life. War, drought, flood, and other natural disasters—as well as the number of co-existing competing states—also increased the probability of a ruler’s unnatural death. The regicide rate exhibits significant variations over time and between different subsamples. Chinese historical regicide rate is generally higher and more volatile than those of European kings but lower than those of Islamic sultans.