Calculating the total number of people who have died in wars throughout history is difficult. As Winston Churchill apparently said, “history is written by the winners”; and this becomes truer the further back we go. The victorious side of any war may exaggerate the number of enemies killed, while glossing over their own losses so as to brag of their military superiority. Equally, if the victor is aware of their public image, they may want to downplay the carnage of war and the atrocities they committed.
What this unfortunately means is that any estimate of the number of deaths caused by war will be very rough indeed. This is further complicated by the lack of consensus amongst historians as to what actually constitutes a war and how to measure the number of deaths due to the effects of war (e.g. famine).
That being said, we can arrive at a ballpark figure by looking at some of the major conflicts in history. The 20th century is described as the “bloodiest”, with an estimated 187 million deaths due to the various wars combined. Almost unbelievably, this number is nearly as high as the total number of deaths due to the entirety of war throughout all history before that point*. An increased world population, combined with huge armies and modern killing machines (explosives, machine guns, chemical weapons, etc.) have made us frighteningly efficient at killing one another. Taking the median estimates of death tolls for various conflicts throughout history, the best estimates put the total death toll due to all wars at 341.7 million people **.
To add a note of optimism, experimental psychologist Steven Pinker argues that violence (including acts of war) is declining. He argues that if you adjust wartime casualties to reflect the population of the time, modern (20th century and after) wars have nothing on more historical conflicts. World War II, for example, tops all lists as the biggest killer (up to 85 million). However, when the numbers are adjusted for the world population at the time, World War II comes out at only number 9, with the rest of the top 10 being before the 20th century. At the top of the list is the An Lushan Rebellion in the Tang Dynasty of China, which may have killed up to one sixth of the entire world population in 755.
As the philosopher George Santayana famously said, “Those who cannot remember the past are condemned to repeat it”. It is therefore important for us not to forget the darker periods of human history, but to learn from them.
* Pre-20th century wars were taken from list of wars by death toll. Where a range was given, the median death toll was used.
** The same list given above was used to obtain medians for estimated death tolls for various conflicts throughout history. Note that conflicts that were part of other (listed) wars ware not included (e.g. the Easter front death toll was not included as this was part of the WWII toll).
By Michael McKenna
Eric Hobsbawm. (February 2002). War and peace. The Guardian [website]. http://www.theguardian.com/education/2002/feb/23/artsandhumanities.highereducation. (Accessed 28 February 2015).
Pinker, S. (2011). The Better Angels of our Nature. presented at the New York, New York: Viking.