1923

1845–1958	Germany [earth sciences]	German naturalist and explorer Alexander von Humboldt lays the basis of modern geography with the publication of Kosmos/Cosmos, in which he arranges geographic knowledge in a systematic fashion.
1923	USA [food and drink]	The US confectioner Forrest Mars invents the Milky Way chocolate bar.
1923	Austria [international organizations]	Interpol, the international police coordination body, is founded following the Second International Judicial Police Conference in Vienna, Austria.
1923	[orchestral music]	The French-born US composer Edgard Varèse completes his orchestral works Hyperprism and Octandre.
1923	[painting]	The German artist Max Beckmann paints Self-Portrait with Cigarette.
1923	[philosophy]	Hungarian cultural philosopher György Lukács publishes Geschichte und Klassenbewusstein: Studien über marxistische Dialektik/History and Class Consciousness: Studies in Marxist Dialectic.
1923	[philosophy]	Chance, Love, and Logic: Philosophical Essays by the Late Charles S Pierce is published posthumously, edited by the US philosopher Morris R Cohen. Though one of the most important US philosophers of the 19th century, Pierce published very little during his lifetime.
1923	[poetry]	The German writer Rainer Maria Rilke publishes his Duineser Elegien/Duino Elegies, and his poetry cycle Die Sonette an Orpheus/Sonnets to Orpheus.
1923	[popular culture]	The Charleston and the Foxtrot emerge as popular dances in the USA.
1923	[psychology]	Austrian psychiatrist Sigmund Freud publishes The Ego and the Id, in which he elaborates his division of the mind into the id, ego, and superego.
1923	United Kingdom [magazines]	The Radio Times, a listeners' guide to radio programmes, is launched in Britain.
1923	[maths]	German mathematician Hermann Oberth publishes Die Rakete zu den Planetenräumen/The Rocket into Interplanetary Space, a treatise on space-flight in which he is the first to provide the mathematics of how to achieve escape velocity.
1923	USA [motor vehicles]	There are more than 13 million passenger automobiles in the USA.
1923	[sculpture]	The French artist Marcel Duchamp completes his sculpture The Large Glass (The Bride Stripped Bare by her Bachelors, Even).
1923	USA [technology]	The Russian-born US engineer Vladimir Zworykin develops the iconoscope in the USA, an image-scanner that can produce electronic signals for reconstitution on the screen of a cathode-ray tube – the basis of television.
1923	[thought and scholarship]	Austrian theologian Martin Buber publishes Ich und Du/I and Thou.
11 January 1923	Germany, France, Belgium [political events]	Because of Germany's failure to meet World War I reparations payments, French and Belgian troops occupy the Ruhr, Germany; its inhabitants respond with passive resistance and sabotage.
13 February 1923	[births and deaths]	Charles (Chuck) E Yeager, US test pilot, the first person to break the sound barrier, born in Myra, West Virginia.
3 March 1923	USA [magazines]	US editor Henry A Luce and US publisher Briton Hadden found the weekly news magazine Time in New York City.
26 March 1923	United Kingdom [radio]	The British Broadcasting Company (BBC) begins broadcasting daily weather forecasts in Britain. The first radio play is also transmitted.
1 May 1923	[births and deaths]	Joseph Heller, US novelist known best for Catch 22 (1961), born in Brooklyn, New York City.
24 May 1923	Ireland [political events]	The Irish nationalist leader Eamon de Valera calls off the guerrilla war, suspended since 27 April, of the anti-Treaty (Anglo-Irish Treaty) republicans who have been fighting for full independence for Ireland because of high losses of men.
26 May 1923	Transjordan [political events]	Emir Abdullah ibn Hussein (second son of King Hussein of the Hejaz) is proclaimed ruler of Transjordan (modern Jordan), which becomes an autonomous state under a British mandate.
9 June 1923	Bulgaria [political events]	A coup in Bulgaria by discontented army officers leads to the fall of the prime minister Alexander Stambolisky (he is assassinated on 15 June).
20 June 1923	[births and deaths]	Francisco ‘Pancho’ Villa, Mexican revolutionary who fought against the regimes of Porfirio Díaz and Victoriano Huerto, is assassinated at his ranch in Parral, Mexico (44).
24 July 1923	Switzerland, Greece, Turkey [treaties]	By the Treaty of Lausanne between Greece, Turkey, and the Allies, ending the Greek–Turkish War, Greece agrees to give up Smyrna, Eastern Thrace, and the islands of Imbros and Tenedos.
2 August 1923	USA [political events]	Following the death of US president Warren G Harding, he is succeeded on 3 August by Vice-President Calvin Coolidge.
1 September 1923	Japan [natural disasters]	Tokyo and Yokohama, Japan, are destroyed by an earthquake estimated to measure 8.3 on the Richter scale; 140,000 die.
13 September 1923	Spain [political events]	The Spanish soldier and politician Miguel Primo de Rivera becomes dictator in Spain (ruling under King Alfonso XIII) after a coup.
26 September 1923	Germany, France, Belgium [political events]	The German chancellor Gustav Stresemann calls for an end to passive resistance to the French and Belgian occupation of the Ruhr (France is making the region work with imported labour while Germany's economy disintegrates).
26 October - 8 November 1923	Australia, New Zealand, Canada, South Africa, United Kingdom [political events]	The Imperial Conference in London, England, recognizes the right of the Dominions (Australia, New Zealand, Canada, and South Africa) to make treaties with foreign powers.
29 October 1923	USA [musicals]	The revue Runnin' Wild, is performed for the first time, at the Colonial Theater, New York City. It includes ‘Charleston’ by Cecil Mack and James P Johnson, which launches a dance craze.
8 November - 9 November 1923	Germany [political events]	In the ‘Munich Putsch’, the German Nazi leader Adolf Hitler and his National Socialist German Workers' (Nazi) Party attempt a coup to overthrow the Bavarian government in Munich, Germany.
15 November 1923	Germany [banking and finance]	The value of the German mark drops to rate of 4,200,000 million to the US dollar; the government introduces a new currency, the rentenmark, to replace the mark.