Earthrise, taken on 24 December 1968 by astronaut William "Bill" Anders during the Apollo 8 space mission. It was the first photograph taken of Earth from lunar orbit.

The 20th century began on 1 January 1901 (MCMI), and ended on 31 December 2000 (MM).[1][2] It was the 10th and last century of the 2nd millennium and was marked by new models of scientific understanding, unprecedented scopes of warfare, new modes of communication that would operate at nearly instant speeds, and new forms of art and entertainment. Population growth was also unprecedented,[3] as the century started with around 1.6 billion people, and ended with around 6.2 billion.[4]

The 20th century was dominated by significant geopolitical events that reshaped the political and social structure of the globe: World War I, the Spanish flu pandemic, World War II and the Cold War. Unprecedented advances in science and technology defined the modern era, including the advent of nuclear weapons and nuclear power, space exploration, the shift from analog to digital computing and the continuing advancement of transportation, including powered flight and the automobile. The Earth's sixth mass extinction event, the Holocene extinction, continued, and human conservation efforts increased.

Major themes of the century include decolonization, nationalism, globalization and new forms of intergovernmental organizations. Democracy spread, and women earned the right to vote in many countries in the world. Cultural homogenization began through developments in emerging transportation and information and communications technology, with popular music and other influences of Western culture, international corporations, and what was arguably a truly global economy by the end of the 20th century. Poverty was reduced and the century saw rising standards of living, world population growth, awareness of environmental degradation and ecological extinction.[5][6] Automobiles, airplanes, and home appliances became common, and video and audio recording saw mass adoption. These developments were made possible by the exploitation of fossil fuel resources, which offered energy in an easily portable form, but also caused concern about pollution and long-term impact on the environment. Humans explored space for the first time, taking their first footsteps on the Moon. Great advances in electricity generation and telecommunications allowed for near-instantaneous worldwide communication, ultimately leading to the Internet. Meanwhile, advances in medical technology resulted in the near-eradication and eradication of many infectious diseases, as well as opening the avenue of biological genetic engineering. Scientific discoveries, such as the theory of relativity and quantum physics, profoundly changed the foundational models of physical science, forcing scientists to realize that the universe was more complex than previously believed, and dashing the hopes (or fears) at the end of the 19th century that the last few details of scientific knowledge were about to be filled in.


At the beginning of the period, the British Empire was the world's most powerful nation,[7] having acted as the world's policeman for the past century.

World powers and empires in 1914, just before the First World War.

Technological advancements during World War I changed the way war was fought, as new inventions such as tanks, chemical weapons, and aircraft modified tactics and strategy. After more than four years of trench warfare in Western Europe, and up to 17 million dead, the powers that had formed the Triple Entente (France, Britain, and Russia, later replaced by the United States and joined by Italy and Romania) emerged victorious over the Central Powers (Germany, Austria-Hungary, the Ottoman Empire and Bulgaria). In addition to annexing many of the colonial possessions of the vanquished states, the Triple Entente exacted punitive restitution payments from them, plunging Germany in particular into economic depression. The Austro-Hungarian and Ottoman empires were dismantled at the war's conclusion. The Russian Revolution resulted in the overthrow of the Tsarist regime of Nicholas II and the onset of the Russian Civil War. The victorious Bolsheviks then established the Soviet Union, the world's first communist state.

Fascism, a movement which grew out of post-war angst and which accelerated during the Great Depression of the 1930s, gained momentum in Italy, Germany, and Spain in the 1920s and 1930s, culminating in World War II, sparked by Nazi Germany's aggressive expansion at the expense of its neighbors. Meanwhile, Japan had rapidly transformed itself into a technologically advanced industrial power and, along with Germany and Italy, formed the Axis powers. Japan's military expansionism in East Asia and the Pacific Ocean brought it into conflict with the United States, culminating in a surprise attack which drew the US into World War II.

After some years of dramatic military success, Germany was defeated in 1945, having been invaded by the Soviet Union and Poland from the East and by the United States, the United Kingdom, Canada, and France from the West. After the victory of the Allies in Europe, the war in Asia ended with the Soviet invasion of Manchuria and the dropping of two atomic bombs on Japan by the US, the first nation to develop nuclear weapons and the only one to use them in warfare. In total, World War II left some 60 million people dead.

The mushroom cloud of the detonation of Little Boy, the first nuclear attack in history, on 6 August 1945 over Hiroshima, igniting the nuclear age with the international security dominating thread of mutual assured destruction in the latter half of the 20th century.

Following World War II, the United Nations, successor to the League of Nations, was established as an international forum in which the world's nations could discuss issues diplomatically. It enacted resolutions on such topics as the conduct of warfare, environmental protection, international sovereignty, and human rights. Peacekeeping forces consisting of troops provided by various countries, with various United Nations and other aid agencies, helped to relieve famine, disease, and poverty, and to suppress some local armed conflicts. Europe slowly united, economically and, in some ways, politically, to form the European Union, which consisted of 15 European countries by the end of the 20th century.

After the war, Germany was occupied and divided between the Western powers and the Soviet Union. East Germany and the rest of Eastern Europe became Soviet puppet states under communist rule. Western Europe was rebuilt with the aid of the American Marshall Plan, resulting in a major post-war economic boom, and many of the affected nations became close allies of the United States.

With the Axis defeated and Britain and France rebuilding, the United States and the Soviet Union were left standing as the world's only superpowers. Allies during the war, they soon became hostile to one another as their competing ideologies of communism and democratic capitalism proliferated in Europe, which became divided by the Iron Curtain and the Berlin Wall. They formed competing military alliances (NATO and the Warsaw Pact) which engaged in a decades-long standoff known as the Cold War. The period was marked by a new arms race as the USSR became the second nation to develop nuclear weapons, which were produced by both sides in sufficient numbers to end most human life on the planet had a large-scale nuclear exchange ever occurred. Mutually assured destruction is credited by many historians as having prevented such an exchange, each side being unable to strike first at the other without ensuring an equally devastating retaliatory strike. Unable to engage one another directly, the conflict played out in a series of proxy wars around the world—particularly in China, Korea, Cuba, Vietnam, and Afghanistan—as the USSR sought to export communism while the US attempted to contain it. The technological competition between the two sides led to substantial investment in research and development which produced innovations that reached far beyond the battlefield, such as space exploration and the Internet.

The international community grew in the second half of the century significantly due to a new wave of decolonization, particularly in Africa. Most of the newly independent states, were grouped together with many other so called developing countries. Developing countries gained attention, particularly due to rapid population growth, leading to a record world population of nearly 7 billion people by the end of the century.

In the latter half of the century, most of the European-colonized world in Africa and Asia gained independence in a process of decolonization. Meanwhile, globalization opened the door for several nations to exert a strong influence over many world affairs. The US's global military presence spread American culture around the world with the advent of the Hollywood motion picture industry and Broadway, jazz, rock music, and pop music, fast food and hippy counterculture, hip-hop, house music, and disco, as well as street style, all of which came to be identified with the concepts of popular culture and youth culture.[8][9][10] After the Soviet Union collapsed under internal pressure in 1991, most of the communist governments it had supported around the world were dismantled—with the notable exceptions of China, North Korea, Cuba, Vietnam, and Laos—followed by awkward transitions into market economies.

Nature of innovation and change

Due to continuing industrialization and expanding trade, many significant changes of the century were, directly or indirectly, economic and technological in nature. Inventions such as the light bulb, the automobile, mechanical computers, and the telephone in the late 19th century, followed by supertankers; airliners; motorways; radio communication and broadcasting; television; digital computers; air conditioning; antibiotics; nuclear power; frozen food; microcomputers; the Internet and the World Wide Web; and mobile telephones affected people's quality of life across the developed world. The quantity of goods consumed by the average person expanded massively. Scientific research, engineering professionalization and technological development—much of it motivated by the Cold War arms race—drove changes in everyday life.

Social change

Martin Luther King Jr., an African American civil rights movement leader (Washington, August 1963)

At the beginning of the century, strong discrimination based on race and sex was significant in most societies. Although the Atlantic slave trade had ended in the 19th century, movements for equality for non-white people in the white-dominated societies of North America, Europe, and South Africa continued. By the end of the 20th century, in many parts of the world, women had the same legal rights as men, and racism had come to be seen as unacceptable, a sentiment often backed up by legislation.[11] When the Republic of India was constituted, the disadvantaged classes of the caste system in India became entitled to affirmative action benefits in education, employment and government.

Attitudes toward pre-marital sex changed rapidly in many societies during the sexual revolution of the 1960s and 1970s. Attitudes towards homosexuality also began to change in the later part of the century.[12][13]

Trauma brought on by events like World War I and World War II, with their military death tolls alone at bare minimum being 29,697,963, and the Spanish Flu, whose death count alone exceeded that, helped make society in many countries more egalitarian and less neglectful of the poor.[14]

Earth at the end of the 20th century

The Blue Marble, Earth as seen from Apollo 17 in December 1972. The photograph was taken by LMP Harrison Schmitt. The second half of the 20th century saw humanity's first space exploration.

Economic growth and technological progress had radically altered daily lives. Europe appeared to be at a sustainable peace for the first time in recorded history[citation needed]. The people of the Indian subcontinent, a sixth of the world population at the end of the 20th century, had attained an indigenous independence for the first time in centuries. China, an ancient nation comprising a fifth of the world population, was finally open to the world, creating a new state after the near-complete destruction of the old cultural order. With the end of colonialism and the Cold War, nearly a billion people in Africa were left in new nation states.

The world was undergoing its second major period of globalization; the first, which started in the 18th century, having been terminated by World War I. Since the US was in a dominant position, a major part of the process was Americanization. The influence of China and India was also rising, as the world's largest populations were rapidly integrating with the world economy.

Terrorism, dictatorship, and the spread of nuclear weapons were pressing global issues. The world was still blighted by small-scale wars and other violent conflicts, fueled by competition over resources and by ethnic conflicts.

Disease threatened to destabilize many regions of the world. New viruses such as the West Nile virus continued to spread. Malaria and other diseases affected large populations. Millions were infected with HIV, the virus which causes AIDS. The virus was becoming an epidemic in southern Africa.

Based on research done by climate scientists, the majority of the scientific community consider that in the long term environmental problems pose a serious threat.[15] One argument is that of global warming occurring due to human-caused emission of greenhouse gases, particularly carbon dioxide produced by the burning of fossil fuels.[16] This prompted many nations to negotiate and sign the Kyoto treaty, which set mandatory limits on carbon dioxide emissions.

World population increased from about 1.6 billion people in 1901 to 6.1 billion at the century's end.[17][18]

Wars and politics

Main articles: International relations of the Great Powers (1814–1919), Diplomatic history of World War I, International relations (1919–1939), Diplomatic history of World War II, Cold War, and International relations since 1989

Map of territorial changes in Europe after World War I (as of 1923).

The number of people killed during the century by government actions was in the hundreds of millions. This includes deaths caused by wars, genocide, politicide and mass murders. The deaths from acts of war during the two world wars alone have been estimated at between 50 and 80 million.[citation needed] Political scientist Rudolph Rummel estimated 262,000,000 deaths caused by democide, which excludes those killed in war battles, civilians unintentionally killed in war and killings of rioting mobs.[19] According to Charles Tilly, "Altogether, about 100 million people died as a direct result of action by organized military units backed by one government or another over the course of the century. Most likely a comparable number of civilians died of war-induced disease and other indirect effects."[20] It is estimated that approximately 70 million Europeans died through war, violence and famine between 1914 and 1945.[21]

Richard Nixon and Leonid Brezhnev aboard the USS Sequoia, June 19, 1973
Hong Kong, under British administration from 1842 to 1997, is one of the original Four Asian Tigers.

Culture and entertainment

Main article: 20th century in literature

I and the Village, 1911, by Marc Chagall, a modern painter


Main article: 20th-century music

Elvis Presley in 1956, a leading figure of rock and roll and rockabilly.

The invention of music recording technologies such as the phonograph record, and dissemination technologies such as radio broadcasting, massively expanded the audience for music. Prior to the 20th century, music was generally only experienced in live performances. Many new genres of music were established during the 20th century.

Film, television and theatre

Charlie Chaplin in his 1921 film The Kid, with Jackie Coogan.

See also: History of film

Film as an artistic medium was created in the 20th century. The first modern movie theatre was established in Pittsburgh in 1905.[37] Hollywood developed as the center of American film production. While the first films were in black and white, technicolor was developed in the 1920s to allow for color films. Sound films were developed, with the first full-length feature film, The Jazz Singer, released in 1927. The Academy Awards were established in 1929. Animation was also developed in the 1920s, with the first full-length cel animated feature film Snow White and the Seven Dwarfs, released in 1937. Computer-generated imagery was developed in the 1980s, with the first full-length CGI-animated film Toy Story released in 1995.

See also: History of Television

Video games

Ralph Baer's Magnavox Odyssey, the first video game console, released in 1972.

Main article: History of video games

Video games—due to the great technological steps forward in computing since the second post-war period—are one of the new forms of entertainment that emerged in the 20th century alongside films.

Art and architecture

The Empire State Building is an iconic building of the 1930s.

Main article: 20th-century art



Main article: 20th century in science

See also: Big Science


The pioneer of computer science, Alan Turing

Multiple new fields of mathematics were developed in the 20th century. In the first part of the 20th century, measure theory, functional analysis, and topology were established, and significant developments were made in fields such as abstract algebra and probability. The development of set theory and formal logic led to Gödel's incompleteness theorems.

Later in the 20th century, the development of computers led to the establishment of a theory of computation.[42] Computationally-intense results include the study of fractals[43] and a proof of the four color theorem in 1976.[44]




Wheat yields greatly increased from the Green Revolution in the world's least developed countries.



A stamp commemorating Alexander Fleming. His discovery of penicillin changed the world of medicine by introducing the age of antibiotics.

Notable diseases

Energy and the environment

Oil field in California, 1938. The first modern oil well was drilled in 1848 by Russian engineer F.N. Semyonov, on the Apsheron Peninsula north-east of Baku.

Engineering and technology

First flight of the Wright brothers' Wright Flyer on December 17, 1903, in Kitty Hawk, North Carolina; Orville piloting with Wilbur running at wingtip.

One of the prominent traits of the 20th century was the dramatic growth of technology. Organized research and practice of science led to advancement in the fields of communication, electronics, engineering, travel, medicine, and war.

Space exploration

Photo of American astronaut Buzz Aldrin during the first moonwalk in 1969, taken by Neil Armstrong. The relatively young aerospace engineering industries rapidly grew in the 66 years after the Wright brothers' first flight.


See also: List of 20th-century religious leaders


See also


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  2. ^ "The 21st Century and the 3rd Millennium When Did They Begin?". United States Naval Observatory. Archived from the original on 2019-10-02. Retrieved 2013-06-07.
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  4. ^ "World Population by Year - Worldometer". Retrieved 2024-01-15.
  5. ^ Wilson, E.O., The Future of Life (2002) (ISBN 0-679-76811-4). See also: Leakey, Richard, The Sixth Extinction : Patterns of Life and the Future of Humankind, ISBN 0-385-46809-1
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  7. ^ Ferguson, Niall (2004). Empire: The rise and demise of the British world order and the lessons for global power. New York: Basic Books. ISBN 978-0-465-02328-8.
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  11. ^ Fleegler, Robert L. Theodore G. Bilbo and the Decline of Public Racism, 1938–1947 Archived 2009-02-06 at the Wayback Machine. Retrieved 23 December 2014
  12. ^ Zadey, Siddhesh (2019-11-25). "Constitution Day: Do We Truly Know the 'Real' Ambedkar?". TheQuint. Retrieved 2021-07-30.
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  16. ^ IPCC AR5 WG1 2013, "Summary for Policymakers, Observed Changes in the Climate System", pp. 10–11: "Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO2 since 1750." (p 11). "From 1750 to 2011, CO2 emissions from fossil fuel combustion and cement production have released 375 [345 to 405] GtC to the atmosphere, while deforestation and other land use change are estimated to have released 180 [100 to 260] GtC." (p. 10).
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  19. ^ Democide See various exclusions
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Further reading