What is the greatest mass murder to live in the entire world?

The title of the greatest mass murderer is often attributed to Mao Zedong, the founding father of the People's Republic of China. His policies, particularly the Great Leap Forward and the Cultural Revolution, are estimated to have led to the deaths of tens of millions of people through famine, forced labor, and persecution. Other historically significant figures include Joseph Stalin and Adolf Hitler, who were also responsible for the deaths of millions through their regimes. The exact numbers can be difficult to ascertain and are subject to historical debate.