1920s
Centuries: 19th century - 20th century - 21st century
Decades: 1870s 1880s 1890s 1900s 1910s - 1920s - 1930s 1940s 1950s 1960s 1970s
Years: 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929
Events and Trends
Technology
Science
- Great advances in quantum mechanics
- Wave mechanics and the Schrödinger equation
- Werner Heisenberg formulates the uncertainty principle
- Paul Dirac's unification of quantum mechanics with special relativity
War, peace and politics
- Rise of communism after World War I
- Irish Civil War
- Southern Ireland gains independence from the United Kingdom in 1922
- Turkish War of Independence
- First Labour Government of Ramsay MacDonald formed in the United Kingdom
- Kellogg-Briand Pact to end war
Economics
- Economic boom ended by "Black Thursday" (October 24, 1929); the stock market crashes, leading to the Great Depression
Culture, religion
- Youth culture of The Lost Generation; Flappers, Charleston, Bobbed Hair
- Prohibition — legal attempt to end consumption of alcohol in the USA
- "The Jazz Age" — Jazz and jazz-influenced dance music widely popular
- Rise of broadcast radio as an entertainment medium
- Start of commercially viable "Talking Pictures" (motion pictures with sound tracks)
- Beginning of surrealist movement
- Beginning of the Art Deco movement
Others
World Leaders
- President Sun Yat-sen (Republic of China)
- President Chiang Kai-shek (Republic of China)
- President Paul von Hindenburg (Germany)
- King Victor Emmanuel III (Italy)
- Prime Minister Benito Mussolini (Italy)
- President W.T. Cosgrave (Irish Free State)
- President Mustafa Kemal (Turkey)
- Emperor Hirohito (Japan)
- Pope Pius XI
- Vladimir Lenin (Soviet Union)
- Joseph Stalin (Soviet Union)
- King George V (United Kingdom)
- Prime Minister David Lloyd George (United Kingdom)
- Prime Minister Andrew Bonar Law (United Kingdom)
- Prime Minister Stanley Baldwin (United Kingdom)
- Prime Minister Ramsay MacDonald (United Kingdom)
- President Woodrow Wilson (United States)
- President Warren G. Harding (United States)
- President Calvin Coolidge (United States)