10 Deadliest Wars in History

The 10 Deadliest Wars in History

Welcome to WatchMojo, and today we’re counting down our picks for the 10 Deadliest Wars in History.

For this list, we’ll be listing the conflicts of the modern era that have seen the largest losses of human life.

Which of these wars did you learn most about in school? Let us know in the comments.

The Second Congo War

The Second Congo War is occasionally known under different titles, such as The Great African War or The Great War of Africa. But one unfortunate aspect of the conflict that remains a constant is the massive loss of life. After starting in 1998, around nine countries were involved in the fighting. This meant many soldiers and civilians suffered fatal consequences. Over three hundred and fifty thousand people died within battle as a result of The Second Congo War. Additionally, a further five million lost their lives due to displacement, disease or exposure. It’s this second statistic that makes The Great African War one of deadliest military conflicts since World War II.

The Russian Civil War

There were a lot of complex historical dominoes that fell into place that led to The Russian Civil War. And after it began, this five-year conflict claimed many lives. The fighting took place between Russian Bolsheviks, the country’s Republic and homegrown Nationalists. Over five million deaths and casualties occurred after all was said and done. Some statistics even lend The Russian Civil War somewhere between seven and twelve million total casualties. In the wake of all this devastation, the number of refugees reached into six digits. And a lack of vital resources made it hard for many citizens to get back on their feet.

The Thirty Years’ War

Historians constantly debate and study the catalysts that eventually lead to such massive, wide-scale military conflicts, especially ones that significantly change socio-political landscapes. Today, the beginnings of The Thirty Years’ War are seen very differently than they once were. The conflict that claimed four to eight million lives was initially seen as being about religious ideologies. But others see the war as a battle of wills and expansion between royal houses in Spain, Austria and France. In the aftermath of the conflict, a few German cities claimed that anywhere between 5,000 and 27,000 of their individual residents had been lost.

The Napoleonic Wars

Portugal, Russia, France, The U.K, Spain and more were all involved during The Napoleonic Wars. During this period, Napoleon Bonaparte oversaw legendary military dominance in the wake of The French Revolution. Upwards of seven million people lost their lives during this decade-plus long period of violence. But the damage didn’t stop there. Infrastructure was affected, horses were stolen, and massive looting took place as the wars raged ever on. Napoleon’s army even suffered one of its greatest losses during The General’s disastrous invasion of Russia in 1812. In that conflict alone, it was estimated that 300,000 soldiers perished.

The Chinese Civil War

Since no formal peace treaty has ever come to pass between the combatants of The Chinese Civil War, some experts state that this 1940s conflict hasn’t technically ended as of June 2022. The conflict came down to a battle between The Republic of China and People’s Republic of China. Throughout the 21st century, they have each maintained legitimacy as national governments. Although a tenuous cease-fire has been in place since 1979, many casualties were recorded before that point. Over eleven million people died throughout the course of this multi-phase war that started back in 1927. There was even a point where fighting stopped to face the threat of World War II. However, the tense conflict resumed in the late forties.

Spanish Conquest of the Inca

Spanish Colonization wasn’t limited just to conquest of the Inca. The country also oversaw violent and deadly invasions of indigenous peoples from Mexico, Peru, Chile and more. But it’s the Spanish Conquest of the Inca that was stated as being one of their most fatal conflicts. Before the fighting began, things weren’t going well within the South American country. Not only were residents battling disease, but a recent civil war left them fractured. Conquistadors took advantage of all of it and launched devastating attacks. By the end of the war, over eight million indigenous Incans died from violent conflict and epidemic disease.

The Ming-Qing Transition

Also known as The Manchu Invasion of China, The Ming-Qing Transition took place over a sixty-plus year period. This struggle mainly occurred between two of China’s monarchical family dynasties, with the latter Qing Dynasty serving as one of China’s largest. The Ming Dynasty started declining during the conflict due to diminished resources and overwhelming opposition. At the same time, the Qing Dynasty continued to expand its power with political moves and bloody conflicts. A startling twenty-five million people died after The Ming-Qing Transition was all said and done. Four decades of fighting had taken an unimaginable toll on everyone involved.

Taiping Rebellion

There are points of history where the number of deaths within a conflict is so large that the final statistics defy reason. The Taiping Rebellion was another period of civil war within Chinese history, this time dating back to the aforementioned Qing Dynasty era. The Qing once again emerged victorious from a rebellion within its control. But the cost of victory was extraordinarily high. The number of total dead after the Taiping Rebellion had concluded was somewhere between twenty and thirty million. And although The Qing Dynasty won the conflict, it still was severely devastated by the Taiping Rebellion.

World War I

Often referred to as “The Great War,” the events of World War I caused an astronomical loss of life. The conflict drew in a number of major world powers from across the globe fighting for their respective causes. During this dark period of world history, there were upwards of sixty-eight million deaths over the course of just over four years of fighting. A number that high in such a relatively short time underlines just how grave this war was after its conclusion in 1918. The changes made to the worldwide socio-political landscape as a result of World War I cannot be overstated.

World War II

As the Axis powers continued a campaign of violence, an alliance between prominent military powers was formed to combat the expanding threat. Even though the war is often depicted in lots of media, it’s still difficult for many to wrap their heads around WWII’s real death toll. The casualties ranged from those lost in military battles to the victims of notorious war crimes. The Atomic Bombings of Hiroshima and Nagasaki alone made up for over two-hundred thousand of those who perished. After a series of large scale invasions and battles, the conflict ended after six years. It’s estimated that as many as 85 million people lost their lives due to World War II.