1931

Events

January

• January 2 – South Dakota native Ernest Lawrence invents the cyclotron, used to accelerate particles to study nuclear physics.
• January 4 – German pilot Elly Beinhorn begins her flight to Africa.
• January 22 – Sir Isaac Isaacs is sworn in as the first Australian-born Governor-General of Australia.
• January 25 – Mohandas Gandhi is again released from imprisonment in India.
• January 27 – Pierre Laval forms a government in France.
• January 30 – Charlie Chaplin comedy drama film City Lights receives its public premiere at the Los Angeles Theater with Albert Einstein as guest of honor. Contrary to the current trend in cinema, it is a silent film, but with a score by Chaplin. Critically and commercially successful from the start, it will place consistently in lists of films considered the best of all time.

  February

• February 4 – Soviet leader Joseph Stalin gives a speech calling for rapid industrialization, arguing that only strong industrialized countries will win wars, while "weak" nations are "beaten". Stalin states: "We are fifty or a hundred years behind the advanced countries. We must make good this distance in ten years. Either we do it, or they will crush us." The first five-year plan in the Soviet Union is intensified, for the industrialization and collectivization of agriculture.
• February 10 – Official inauguration ceremonies for New Delhi as the capital of India begin.
• February 16 – Pehr Evind Svinhufvud is elected president of Finland.
• February 21 – Peruvian revolutionaries hijack a Ford Trimotor aeroplane, and demand that the pilot drop propaganda leaflets over Lima.

  March

• March 5 – The British viceroy of India and Mohandas Gandhi sign the Gandhi–Irwin Pact.
• March 7 – The Finnish Parliament House opens in Helsinki, Finland.
• March 11 – The Ready for Labour and Defence of the USSR programme, abbreviated as GTO, is introduced in the Soviet Union.
• March 23 – Indian revolutionary leaders Bhagat Singh, Shivaram Rajguru and Sukhdev Thapar are hanged for conspiracy to murder in the British Raj.
• March 31 – An earthquake destroys Managua, Nicaragua, killing 2,000 people.

  April

• April 1 – The Second Encirclement Campaign against Jiangxi Soviet in China is launched by the Kuomintang government, to destroy the Communist forces in Jiangxi Province.
• April 6 – The Portuguese government declares martial law in Madeira and in the Azores, because of the Madeira uprising in Funchal.
• April 12 – Municipal elections in Spain, which are treated as a virtual referendum on the monarchy, result in the triumph for the republican parties.
• April 14 – The Second Spanish Republic is proclaimed in Madrid. Meanwhile, as a result of the victory of the Republican Left of Catalonia, Francesc Macià proclaims in Barcelona the Catalan Republic, as a state of the Iberian Federation.
• April 15 – Assassination of Giuseppe Masseria, New York City Mafia boss.
• April 17 – After the negotiations between the republican ministers of Spain and Catalonia, the Catalan Republic becomes the Generalitat of Catalonia, a Catalan autonomous government inside the Spanish Republic.
• April 22 – Austria, the UK, Denmark, Germany, Italy, Sweden and the United States recognize the Spanish Republic.
• April 25 – The automobile manufacturer Porsche is founded by Ferdinand Porsche in Stuttgart.

  May

• May 1 – Construction of the Empire State Building is completed in New York City.
• May 4 – Kemal Atatürk is re-elected president of Turkey.
• May 5 – İsmet İnönü forms a new government in Turkey.
• May 11 – The Creditanstalt, Austria's largest bank, goes bankrupt, beginning the banking collapse in Central Europe that causes a worldwide financial meltdown.
• May 13 – Paul Doumer is elected president of France.
• May 14 – Ådalen shootings: Five people are killed in Ådalen, Sweden, when soldiers open fire on an unarmed trade union demonstration.
• May 15
• * The Chinese Communists inflict a sharp defeat on the Kuomintang forces.
• * Pope Pius XI issues the encyclical Quadragesimo anno, on the "reconstruction of the social order".
• May 31 – The Second Encirclement Campaign against Jiangxi Soviet ends in the defeat of the Kuomintang.

  June

• June–November – 1931 China flood: the Yangtze and Huai Rivers flood in a populous region, leaving an estimated 422,000 dead with many more dying of consequential starvation and disease in the aftermath.
• June 5
• *German Chancellor Heinrich Brüning visits London, where he warns British Prime Minister Ramsay MacDonald that the collapse of the Austrian banking system, caused by the bankruptcy of the Creditanstalt, has left the entire German banking system on the verge of collapse.
• *Anti-Chinese rioting occurs in Pyongyang. Approximately 127 Chinese people are killed, 393 wounded, and a considerable number of properties are destroyed by Korean residents.
• June 14 – Saint-Philibert disaster: The overloaded pleasure craft Saint-Philibert, carrying trippers home to Nantes from the Île de Noirmoutier, sinks at the mouth of the River Loire in France; over 450 drown.
• June 19
• * In an attempt to stop the banking crisis in Central Europe from causing a worldwide financial meltdown, U.S. President Herbert Hoover issues the Hoover Moratorium.
• * The Geneva Convention relative to the treatment of prisoners of war enters into force.
• June 23–July 1 – Wiley Post and Harold Gatty accomplish the first round-the-world flight in a single-engine plane, flying eastabout from Roosevelt Field, New York, in 8 days, 15 hours, 51 minutes.

  July

• July 1 – The rebuilt Milano Centrale railway station officially opens in Italy.
• July 9 – Irish racing driver Kaye Don breaks the world water speed record at Lake Garda, Italy.
• July 10 – Norway issues a royal proclamation claiming the uninhabited part of eastern Greenland as Erik the Red's Land.
• July 13 – Royal soldiers shoot and kill 22 people demonstrating against the Maharaja Hari Singh, of the Indian princely state of Kashmir and Jammu.
• July 16 – Emperor Haile Selassie signs the first Constitution of Ethiopia.
• July 20 – A violent tornado strikes the city of Lublin, Poland.

  August

• August 2 – Murder of Paul Anlauf and Franz Lenck: Two Berlin police officers are killed by Communists.
• August 9 – A referendum in Prussia for dissolving the Landtag ends with the "yes" side winning 37% of the vote, which is insufficient for calling the early elections. The elections are intended to remove the Social Democratic Party government of Otto Braun. Supporting the "yes" side were the NSDAP, the DNVP and the Communist Party, while supporting the "no" side were the SPD and Zentrum.
• August 24 – The Labour Government of Ramsay MacDonald resigns in Britain, replaced by a National Government of people drawn from all parties, also under MacDonald.

  September

• September 7 – The Second Round Table Conference on the constitutional future of India opens in London; Mahatma Gandhi represents the Indian National Congress.
• September 10 – The worst hurricane in British Honduras history kills an estimated 1,500.
• September 18 – The Japanese military stages the Mukden Incident, an explosion blamed on Chinese dissidents and used as a pretext for the Japanese invasion of Manchuria.
• September 19 – The United Kingdom abandons the gold standard.
• September 20 – Held at gunpoint, the Chinese commander of Kirin province announces the annexation of that territory to Japan.

  October

• October 5 – American aviators Clyde Edward Pangborn and Hugh Herndon Jr., complete the first non-stop flight across the Pacific Ocean, flying their plane, Miss Veedol, from Misawa, Japan, to East Wenatchee, Washington, in 41½ hours.
• October 11 – A rally in Bad Harzburg, Germany leads to the Harzburg Front being founded, uniting the NSDAP, the DNVP, the Stahlhelm and various other right-wing factions.
• October 24 – The George Washington Bridge across the Hudson River in the United States is dedicated; it opens to traffic the following day. At, it nearly doubles the previous record for the longest main span in the world.
• October 27 – The United Kingdom general election results in the victory of the National Government, and the defeat of Labour Party, in the country's greatest ever electoral landslide.

  November

• November 7
• * The Chinese Soviet Republic is proclaimed by Mao Zedong.
• * Red China News Agency is officially founded, and news wire service start in Ruijin, Jiangxi Province, China.
• November 8
• * French police launch a large-scale raid against Corsican bandits.
• * The Panama Canal is closed for a couple of weeks, due to damage caused by earthquakes.
• November 26 – Heavy hydrogen, later named deuterium, is discovered by American chemist Harold Urey.

  December

• December 5 – The original Cathedral of Christ the Saviour in Moscow is demolished, by order of Joseph Stalin.
• December 8 – Carl Friedrich Goerdeler is appointed Reich Price Commissioner, in Germany to enforce the deflationary policies of the Brüning government.
• December 9 – The Spanish Constituent Cortes approves the Spanish Constitution of 1931, effectively establishing the Second Spanish Republic.
• December 10 – Niceto Alcalá-Zamora is elected president of the Spanish Republic.
• December 11 – The Parliament of the United Kingdom enacts the Statute of Westminster, which establishes a status of legislative equality between the self-governing dominions of the Commonwealth of Australia, Canada, the Irish Free State, Newfoundland, the Dominion of New Zealand and the Union of South Africa.
• December 13 – Wakatsuki Reijirō resigns as Prime Minister of Japan.
• December 19 – The UAP/Country Coalition, led by Joseph Lyons, defeats the Australian Labor Government, led by Prime Minister James Scullin. Coming in the aftermath of two splits in the Labor Party, the election comes about due to the defeat of the Scullin government on the floor of the House of Representatives – to date, it is the last federal election where a one-term government was defeated. Lyons will be sworn in January 6th the following year, but not before disbanding the Coalition, after the UAP wins enough seats to form a government in its own right.