( Rossum's Universal Robots ) ( 1921 ) – the play that introduced the word robot to the world – were organic artificial humans, the word " robot " has come to primarily refer to mechanical humans, animals, and other beings.

* 1921 – Robert Cliche, Canadian politician and magistrate ( d. 1978 )

* 1921 – Black Friday: mine owners announce more wage and price cuts, leading to the threat of a strike all across England.

* 1921 – Tove Maës, Danish actress ( d. 2011 )

* 1921 – The British install the son of Sharif Hussein bin Ali ( leader of the Arab Revolt of 1916 against the Ottoman Empire ) as King Faisal I of Iraq.

* 1921 – Georg Alexander, Duke of Mecklenburg ( d. 1996 )

* 1921 – Leo Penn, American director ( d. 1998 )

* 1921 – Ernest Angley, American evangelist and broadcaster

* 1921 – J. James Exon, American politician ( d. 2005 )

They won the first eight matches in succession including a 5 – 0 whitewash in 1920 – 1921 at the hands of Warwick Armstrong's team.

* 2008 – Jake Warren, Canadian diplomat ( b. 1921 )

* 2012 – N. K. P. Salve, Indian politician ( b. 1921 )

The most important Canadian theorist was an American immigrant, Henry Wise Wood, president of the United Farmers of Alberta ( UFA ) during that movement's time as the governing party of the province ( 1921 – 1935 ).

* 1921 – Jack Kramer, American tennis player ( d. 2009 )

* 1921 – Major League Baseball Commissioner Kenesaw Mountain Landis confirms the ban of the eight Chicago Black Sox, the day after they were acquitted by a Chicago court.

* 1921 – Marilyn Maxwell, American actress ( d. 1972 )

* 1921 – Richard Adler, American songwriter and composer ( d. 2012 )

* 1921 – Hayden Carruth, American poet and critic ( d. 2008 )

* 1999 – Byron Farwell, American historian ( b. 1921 )

The second generation was led by Fernand Braudel ( 1902 – 1985 ) and included Georges Duby ( 1919 – 1996 ), Pierre Goubert ( 1915 – 2012 ), Robert Mandrou ( 1921 – 1984 ), Pierre Chaunu ( 1923 – 2009 ), Jacques Le Goff ( 1924 – ) and Ernest Labrousse ( 1895 – 1988 ).

When Peter B. Kyne ( Pride Of Palomar, 43 ) informed us in 1921 that we had an instinctive dislike for the Japanese, did the heated debates of the Californians settle the truth or falsity of the proposition??

* 1842 – Peter Kropotkin, Russian anarchist ( d. 1921 )

* 1921 – Peter Whalley, Canadian cartoonist and sculptor ( d. 2007 )

* Peter I, King of Serbia ( 1903 – 1918 ), King of Serbs, Croats, and Slovenes ( 1918 – 1921 )

Lord Peter begins his hobby of investigation by recovering The Attenbury Emeralds in 1921.

* 1921 – Peter Ruckman, American Baptist minister

* Paul Bew, Henry Patterson, Peter Gibbon, Northern Ireland, 1921 – 2001, Serif, London, 2002, ISBN 978-1-897959-38-1

* December 9 – Peter Kropotkin, Russian anarchist ( d. 1921 )

* July 11 – King Peter I of Serbia ( d. 1921 )

* March 29 – Peter Ustinov, English actor and director ( b. 1921 )

Peter Kropotkin ( 1842 – 1921 ) was a Russian prince and anarchist.

Amongst other poets of the second half of the twentieth century, the names of Roland Mathias ( 1915 – 2007 ), Leslie Norris ( 1921 – 2006 ), John Ormond ( 1923 – 90 ), Dannie Abse ( 1923-), Raymond Garlick ( 1926-), Peter Finch ( 1947-) and Paul Groves ( 1947-) have a significant place.

Amongst other poets of the second half of the twentieth century, the names of Roland Mathias ( 1915 – 2007 ), Leslie Norris ( 1921 – 2006 ), John Ormond ( 1923 – 1990 ), Dannie Abse ( born 1923 ), Raymond Garlick ( born 1926 ), Peter Finch ( born 1947 ), and perhaps also Paul Groves ( born 1947 ) have a significant place.

* Alexandra of Greece ( 1921 – 1993 ), Princess of Greece and Denmark, who married King Peter II of Yugoslavia ( 1923 – 1970 ).

* Peter Townsend Barlow ( 1857 – 1921 ), New York City Magistrate

A., " Peter of Blois " in Somerset Historical Essays ( 1921 )

Queen Alexandra of Yugoslavia (, ;) ( 25 March 1921 – 30 January 1993 ) was the wife of the last King of Yugoslavia, Peter II and mother of Alexander, Crown Prince of Yugoslavia.

* Peter Mills ( UK politician ) ( 1921 – 1993 ), British Conservative Member of Paraliament for Devon West

* Peter Hansen ( actor ) ( born 1921 ), American actor

* Peter Sturges Ruckman ( 1921 – present ), a Baptist preacher, wrote many books: a series of uniformly bound books that are claimed to be commentaries on various Bible books, topical books on Bible-related subjects and books related to Bible text and translation issues.

* King Peter I Karađorđević of Serbia, later Peter I King of the Serbs, Croats and Slovenes ( i. e. of Yugoslavia ) ( 1844 – 1921 )

* Peter I of Serbia ( 1844 – 1921 ): 1862

Pierre-Joseph Proudhon ( 1809 – 1865 ) and Peter Kropotkin ( 1842 – 1921 ) wrote about anarchist forms of socialism in their books.