War By the Numbers: Which One Was Deadliest?

War and conflict are significant contributors to human death. Millions of people have died over the centuries during these battles, often started for reasons that involve conquest or dominion.

Although we often think of modern wars as having the most casualties, that is not always the case. Here are the deadliest conflicts recorded in human history.

1. World War II

With the Allied vs. Axis powers conflict, the Sino-Japanese battles, and the side wars that waged during this conflict, up to 85 million people were killed from 1937-1945. Although World War II’s official start is 1939, some battles started up to 24 months earlier that became part of the overall conflict.

2. The Transition from Ming China to Qing China

The Ming-Qing Transition was a conflict that took a confirmed 25 million lives, and probably killed millions more. This conflict lasted for almost 70 years during the 17th century as multiple kingdoms and dynasties fought for power and control.

3. Spanish Conquest of the Americas

This conflict took an estimated 25 million lives in direct battle and possibly claimed double that figure with disease introduction. As Europeans came to conquer the Americas for riches, multiple plagues ripped through the region, wiping cultures off the map.

4. World War I

Up to 40 million people may have died because of the various battles that happened in the first global war. After coming out of this conflict, the world had a flu epidemic that took up to 50 million more lives. Those figures don’t account for the Russian Civil War’s casualties that took place during this period.

5. Chinese Civil War

This conflict pitted the ROC against the PRC to see what government style would dominate in China. The communists would eventually win, with the democratic officials fleeing to Taiwan for safety. Almost 8 million people died in this conflict.

6. The Mongol Conquests

The battles that the Mongol Empire started against several Eurasian states took up to 40 million lives. When you add the Bubonic Plague that likely came along during this migration, another 200 million were killed, making this era in human history the deadliest ever recorded. It was over 160 years of sporadic war.

The last 50 years have been the most peaceful our planet has experienced over the last ten centuries. Our continued efforts to avoid war can continue this trend.