War casualties since the dawn of mankind are overwhelming, and there are no estimates revealing how many have died in all conflicts throughout history. The amount of people who were killed in wars largely depends on the war or the century. According to PBS, over 100 million died in conflicts during the 20th century alone.
History Guy notes that the 20th century was the bloodiest century in human history. When factoring in the number of revolutions and World Wars I and II, the number of people who suffered surpasses all previous centuries. According to History Learning Site, World War I killed 8.5 million people, with the total number of missing and wounded held at 37 million. Many people celebrated when various European nations were going to war, but they were shocked at the number of casualties and destruction. World War I was subsequently called "the war to end all wars," but history shows otherwise. History World reports that casualties from World War II fall anywhere between 35 million to 60 million people. War World II is considered the most devastating war in human history, when adding the number of people who died in bomb strikes and concentration camps. Technological advances played a heavy role in the number of war casualties incurred around the world.