The 20th century is defined as the time period running from January 1, 1901 to December 31, 2000.

The Chinese, Russian, German, Ottoman, and Austro-Hungarian empires dissolved in the first half of the century, with all but the British, French, and Japanese empires collapsing during the course of World War I, and Russia transformed into communist state of Soviet Union. The inter-war years saw a Great Depression cause a massive disruption to the world economy. Shortly afterwards, World War II broke out, pitting the Allied powers (chiefly the Soviet Union, the United States, and the United Kingdom) against the Axis powers (Nazi Germany, the Empire of Japan, and Italy) which eventually resulted in a total victory for the Allies, at the cost of over 60 million lives (including millions of civilians) and the complete devastation of many nations. Remaining colonial empires dissolved shortly after the war. As a means of preventing future world wars, the United Nations was formed; however, competition between the two new superpowers, the Soviet Union and the United States, resulted in the Cold War, which would dominate geopolitical life for the next 45 years. The Soviet Union collapsed internally in 1991, resulting in the United States taking on sole superpower status.

Monty Python (sometimes known as The Pythons) was a British surreal comedy group who created Monty Python's Flying Circus, a British television comedy sketch show that first aired on the BBC on 5 October 1969. Forty-five episodes were made over four series. The Python phenomenon developed from the television series into something larger in scope and impact, spawning touring stage shows, films, numerous albums, several books and a stage musical as well as launching the members to individual stardom. The group's influence on comedy has been compared to The Beatles' influence on music.

The television series, broadcast by the BBC from 1969 to 1974, was conceived, written and performed by members Graham Chapman, John Cleese, Terry Gilliam, Eric Idle, Terry Jones, and Michael Palin. Loosely structured as a sketch show, but with an innovative stream-of-consciousness approach (aided by Gilliam's animation), it pushed the boundaries of what was acceptable in style and content. A self-contained comedy team responsible for both writing and performing their work, the Pythons' creative control allowed them to experiment with form and content, discarding rules of television comedy. Their influence on British comedy has been apparent for years, while in North America it has coloured the work of cult performers from the early editions of Saturday Night Live through to more recent absurdist trends in television comedy. "Pythonesque" has entered the English lexicon as a result.