From ancient times to the present, some rulers have dominated their countries with iron fists. Far from being “ benevolent dictators,” these ruthless leaders have quashed dissent and cemented their power with programs that led to thousands and sometimes millions of deaths from executions, ill-fated wars, or widespread starvation due to poor economic management.

To compile a list of the most ruthless rulers in history, 24/7 Tempo reviewed biographies and historical articles on several sites, among them History and Britannica.

Click here to read about the most ruthless rulers in history

Not all are men. There are three women on the list: Wu Zetian ruled China from 690 to 705. She maintained her power for that long by executing her rivals, including family members. Between 1828 and 1861, Madagascar’s Ranavalona I was known as Ranavalona the Cruel for her systematic torturing and killing of opponents and foreigners. Mary I reigned over England and Ireland from 1553 to 1558. Known as “Bloody Mary,” she burned Protestant heretics at the stake. (These are the most famous female rulers in history.)

Eventually, citizens in many countries have grown weary of their rulers’ cruelty and overthrown them. Nicolae Ceaușescu was tried and executed for his crimes soon after the Iron Curtain fell in Romania. Libya’s Muammar Gaddafi met a similar fate after a rebel uprising. (Here’s a list of 26 rulers who were killed by their own people.)

Yet Kim Jong-un remains in power in North Korea, threatening the world with nuclear weapons and keeping his countrymen in line with repressive and lethal tactics – for now.