The 2020 Summer Olympics in Tokyo have been officially postponed due to the coronavirus pandemic. The International Olympic Committee (IOC) and Prime Minister Shinzo Abe of Japan agreed to push the start date back to 2021 after Canada, Australia, and other countries announced they would not send athletes to the Summer Games this July.

The Summer Olympics is the biggest sporting event in the world, typically bringing more than 10,000 athletes from dozens of countries together every four years, The New York Times reports.

It's extremely rare for the Summer or Winter Olympics to be postponed or canceled. Since 1896, when the modern Olympic Games began, it has happened only six times—and it usually requires a war.

The Olympic Games were canceled during World War I and World War II. The 1940 Summer Games, scheduled to take place in Tokyo, were postponed due to war and moved to Helsinki, Finland, where they were later canceled altogether. The current coronavirus pandemic marks the first time the competition has ever been temporarily postponed for a reason other than war. Here's the full list.

  1. 1916 Summer Olympics // Berlin, Germany
  1. 1940 Summer Olympics // Tokyo, Japan and Helsinki, Finland
  1. 1940 Winter Olympics // Garmisch-Partenkirchen, Germany
  1. 1944 Summer Olympics // London, United Kingdom
  1. 1944 Winter Olympics // Cortina d'Ampezzo, Italy
  1. 2020 Summer Olympics // Tokyo, Japan