War and Peace Over the Long Run



Battle of Scheveningen, by Jan Abrahamsz Beerstraaten / Wikimedia Commons


By Dr. Max Roser
Economic Researcher
Oxford Martin School


The past was not peaceful

It would be wrong to believe that the past was peaceful. One reason why some people might have this impression is that many of the past conflicts feature less prominently in our memories, they are simply forgotten.

An overview of all the conflicts that we have historical knowledge and an estimate of the number of fatalities of is shown in the visualization below.

The red circles visualize all conflicts in the Conflict Catalog (here) authored by Peter Brecke. Brecke’s dataset contains information on 3708 conflicts, but in the more distant past it is still incomplete and for many past conflicts Brecke is either lacking an estimate of the number of fatalities or we can suspect that entire conflicts are completely unknown.

Global deaths in conflicts, since 1400 – Max Roser1


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In Europe the second half of the 20th century was extraordinarily peaceful

The following Gantt chart shows the years in which European countries (or their predecessor states) took part in an international wars. Below the country-by-country visualization we see the sum (per half century) of all years in which European countries fought wars.

Years in which European countries took part in an international war, 1500-2000 – Max Roser2


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Percentage of years in which the ‘Great Powers’ fought one another, 1500-2015 – Max Roser 3


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Death rates from military conflicts in England, 1170s-1900s – Clark (2008)4


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Wars and Other Atrocities in the Very Long Run

A list of ‘Dictionaries or Encyclopedias of Wars and Battles’ is presented by Peter Brecke in his article ‘The Long-Term Patterns of Violent Conflict in Different Regions of the World’.5

‘The 100 Worst Atrocities’ over the last millennia – New York Times6


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The 20th Century

International battle deaths per 100,000 people, 20th Century – Acemoglu (2012)7


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Data Sources

Uppsala Conflict Data Program (UCDP) and Peace Research Institute Oslo (PRIO)
  • Data: Armed conflict data
  • Geographical coverage: Global
  • Time span: 1948-2008
  • Available at: Online here
Peter Brecke’s Conflict Catalog
  • Data: 3708 conflicts, data on parties, fatalities, date and duration
  • Geographical coverage: Global
  • Time span: 1400 CE to present
  • Available at: Online at Clio Infra
  1. The Conflict Catalog (Violent Conflicts 1400 A.D. to the Present in Different Regions of the World) authored by Peter Brecke contains information on 3708 conflicts, data on parties, fatalities, date and duration between the year 1400 and 2000.
    It is available at the Center for Global Economic History here.

    The data on the military death rate after 1946 is taken from the Human Security Report Project, which takes data from the PRIO Battle Deaths Dataset v.3.0. The page presenting this data is online here.

  2. These data are taken from the CLIO Infra Project. The original source of these data is the Conflict Catalog by Peter Brecke, which you can access directly here.

  3. The data are taken from figure 5-12 in Pinker (2011) – The Better Angels of Our Nature: Why Violence Has Declined. Viking Adult.

    The original source of the data are Levy & Thompson (2011) – The Arc of War (Origins, Escalation, and Transformation), The University of Chicago Press, Chicago and London

  4. The Source is Clark (2008) – A Farewell to Alms: A Brief Economic History of the World. Princeton University Press.

    The line shows a fifty year moving average of combat death rates in England.

  5. The article is online here, and the list can be found in the appendix.

  6. This infographic is taken from the New York Times; the original is here.

    The source of the data is White (2011) – The Great Book of Horrible Things – The Definitive Chronicle Of History’s 100 Worst Atrocities. W. W. Norton & Company.

    The website of the book is here.

  7. Acemoglu (2012) – The world our grandchildren will inherit: the rights revolution and beyond. Essay prepared for Economic Possibilities for Our Grandchildren edited by Ignacio Palacios-Huerta, MIT, 2012.

    The article is online at the website of the MIT here.

    The data used for this figure are the “best estimates” from the PRIO-UPSALA dataset from Lacina and Gleditsch (2005) – ‘Monitoring Trends in Global Combat: A New Dataset of Battle Deaths’, European Journal of Population vol. 21(2–3): 145–166.

    The website of the PRIO database is here.

    International battle deaths are those recorded in conflicts between two or more recognized states.



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