It is difficult to definitively identify the "bloodiest king in the history of mankind" as there have been many rulers throughout history who have been responsible for widespread death and destruction. However, some historical figures known for their brutal tactics and large-scale atrocities include: Genghis Khan, the founder of the Mongol Empire, is estimated to have killed as many as 40 million people during his conquests. Timur, also known as Tamerlane, was a 14th-century conqueror from Central Asia who is estimated to have killed 17 million people during his campaigns. Vlad III Dracula, a 15th-century prince of Wallachia (now part of Romania), was known for his brutal punishments and is said to have impaled thousands of his enemies. t's worth noting that the exact number of casualties attributed to these figures is often subject to debate and can be difficult to verify, but they are generally considered to have been some of the bloodiest rulers in history. William