The exact number of people who have died in war throughout history is not precisely known and varies depending on how such deaths are defined and what conflicts are included. Estimates vary widely, reaching hundreds of millions or even billions. Some estimations suggest around 150 million to 200 million people died in the 20th century alone from war-related events, including both combatants and civilians. However, these numbers can be challenging to verify due to gaps in historical records and differing interpretations of war causalities.