The Twentieth Century

The twentieth century was the period beginning 1 January 1901 and ending 31 December 2000, according to the Gregorian calendar. It was a century marked by major political, economic, and technological change, during which the world population tripled.

It was defined by two world wars, the Cold War, the collapse of imperial empires, and the creation of international bodies such as the United Nations. It also saw advances in electricity, aviation, atomic science, antibiotics, and computers.

World Wars

The First World War (1914–1918) destroyed the Ottoman, Russian, Austro-Hungarian, and German empires. The Second World War (1939–1945) became the deadliest in history, encompassing the Holocaust and the use of nuclear weapons on Hiroshima and Nagasaki in 1945.

The Cold War and the end of empires

After 1945, the United States and the Soviet Union entered into political, military, and ideological competition known as the Cold War. During this period, many Asian and African countries gained independence; Somalia gained independence on 1 July 1960 when the North and South united. The Cold War ended with the collapse of the Soviet Union in 1991.

Science and technology

The century saw the emergence of relativity theory and quantum mechanics, which became the foundation of modern physics. The first powered aircraft flew in 1903; in 1969 humans landed on the moon. In health, vaccines and antibiotics reduced child mortality; in 1980 smallpox was declared eradicated.

Society and economics

There was expansion of women's voting rights, urbanization, and universal education. By the end of the century, the internet and the mobile phone began to transform communication and commerce, while environmental issues such as climate change entered the global agenda.