Top 5 Largest Wars of the 20th Century

Craig Walton Craig Walton / Published Feb 3, 2017, 8:26 AM

The 20th century (1901-2000) saw numerous wars, murders on a massive scale, and military conflicts, resulting in millions of lives lost on the national and global stage. These wars include those most of us have heard of, such as World War I or World War II. But there are also other conflicts and mass-scale deaths—that were almost as large and catastrophic—that many of us don't know about.

We believe it's always a good idea to look back and examine history. The moment we start forgetting the past is the moment we repeat the same mistakes. That's why we’ve compiled a list of the top 5 largest, deadliest wars or conflicts of the 20th century, defined here by the number of casualties. The list of casualties is estimated, but it still helps reveal the scale of the various wars.

20th Century Wars, Conflicts, and Rules with the Highest Casualties

1.  World War II:  (65 million)   1939 - 1945

The name of the war says it all.  It truly was a “World War.” It’s estimated that 65 to 80 million men, women, and children lost their lives during World War II. Scale-wise, the second world war affected at least a hundred countries and racked up body counts in 27 of these, making it the bloodiest war of all time. Hitler’s Germany surrendered on April 29, 1945 bringing the chaos to a close.

2.  World War I:  (25 million)   1914 - 1918

25 million of the 70 million military personnel who participated in World War I died; that’s just a little less than half. And the suffering didn’t end there; the financial, social, and political aftermath of the war left Germany in ruins, eventually giving way to the movement that would bring Hitler to power and launch World War II.

3.  The Great Purge:  (13 million)   1937 - 1938

Joseph Stalin, the leader of the Soviet Union, headed a mass execution of those opposing the Communist party. Some 13 million Russians were murdered under Joseph Stalin, leader of the Soviet Union, during the Great Purge, a horrific mass execution of all those who opposed the Communist Party. Those who weren’t killed were imprisoned, and Communism stayed in Russia for the next 50 to 60 years until its collapse in 1991.

4. Cultural Revolution:  (11 million)   1966 - 1976

Much like the Great Purge, Mao Zedong’s Cultural Revolution in China turned into a party-led bloodbath that claimed approximately 11 million lives. Zedong, chairman of the Communist Party of China, felt he was ensuring Communism’s continued existence by indoctrinating Chinese youth (called Red Guards) and killing anyone, even those within his own party, who he thought might be gaining greater power than himself. His actions made way for one of the largest civil wars in Chinese history.

5.  Belgian-Congo Free State Rule:  (10 million)   1876 - 1908 

On the cusp of the 20th century, King Leopold II of Belgium took personal control over the Congo. His rule led to human exploitation for the rubber trade and gathering of other resources, murder, mutilation, wars and rebellions when Congolese refused to acknowledge Belgian rule or gather rubber, disease, and suffering on a massive scale. About 10 million people, or half the Congolese population at the time, died during the Free State rule. Belgian cruelty was eventually checked by media attention and movements in the US and UK.

History as Our Teacher

Why do we study history at all? The answer is quite clear: it is to learn from the misdeeds of our ancestors and others and especially from the misuse of power. Genocide and war usually begin when one person comes into too much power, and in almost every scenario, those with power spend the rest of their lives fearing it will be taken away from them. It’s hard to imagine losing one’s humanity to the point of mass murder, but as the saying goes, absolute power corrupts absolutely.

We at Low VA Rates are thankful to live in a country in which power is distributed and, for the most part, kept under control. The United States’ system of government may not be perfect, and yes, corruption can and does occur at every level, but we believe the Constitution and design of our government help protect against autocracy and limit the power of America’s leaders. Additionally, as we reflect on the millions of American lives lost in these military conflicts, we express our undying gratitude and appreciation for our veterans, and for those troops currently serving.

Thousands of U.S. troops deploy every year and sacrifice their lives to preserve our freedoms.  Hopefully, future generations will continue to be willing to sacrifice their lives to prevent these atrocities from plaguing our history.