In shortNumber 1 in our ranking is World War II, followed by World War I and The Russian Revolution.
Choosing the events that changed the 20th century means choosing the world we live in today: its borders, its technology and its fears. We weighed the reach of each event, how many people it affected and how long its mark has lasted.
Would you change the order, or is one missing? Vote below or add your own.
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1. World War II
1939–1945
The deadliest conflict in history, with the Holocaust as its most terrible crime. It shaped the post-war world: the United Nations, a divided Europe and the start of the Cold War.
2. World War I
1914–1918
It brought down four empires and redrew the map of Europe and the Middle East. Its poorly settled aftermath paved the way for the next war.
3. The Russian Revolution
1917
It toppled the tsar and gave rise to the Soviet Union, the first communist state. Its existence shaped world politics for more than seventy years.
4. The atomic bombings of Hiroshima and Nagasaki
August 1945
The only use of nuclear weapons in war. It opened the atomic age and the fear of total destruction that hung over the whole Cold War.
5. The fall of the Berlin Wall
9 November 1989
It symbolised the end of a divided Europe and hastened German reunification. Two years later the Soviet Union dissolved.
6. The Moon landing
20 July 1969 · Apollo 11
Neil Armstrong and Buzz Aldrin became the first people to walk on another world, watched by hundreds of millions. It was the high point of the space race.
7. The decolonisation of Asia and Africa
From 1945 · India gains independence in 1947
Dozens of countries won independence from European powers in barely three decades. It changed the political map of the planet and the make-up of the United Nations.
8. The Wall Street Crash and the Great Depression
From October 1929
The collapse of the New York stock market triggered the worst economic crisis of the century. Unemployment and poverty fuelled the extremism of the 1930s.
9. The birth of the internet and the web
ARPANET in 1969 · The web in 1989
A military and academic network ended up connecting billions of people. Tim Berners-Lee proposed the World Wide Web at CERN and changed how we communicate and work.
10. The Chinese Revolution
1949
The communist victory in the civil war created the People's Republic of China. It set in motion the transformation of the world's most populous country for much of the century.
Frequently asked questions
What was the most important event of the 20th century?
In our ranking, World War II, for its reach and because it shaped the world that followed. World War I and the Russian Revolution complete the podium.
Why is the Moon landing ranked below other events?
Because we weighed the impact on people's lives and on the world order. As a scientific and symbolic milestone, it has no rival.
Would you change the order?
Tell us what's missing, what shouldn't be here or what you'd put at number 1.