1905 followed by 1906
October
October 1
A Czech worker, František Pavlík (b. 1885), is bayoneted to death during a demonstration for a Czech university in Brno. This event is the motivation for a piano sonata, 1. X. 1905, by composer Leoš Janáček, which premières on 27 January 1906.
Turkish Association football team Galatasaray is founded in Istanbul.
October 2 – HMS Dreadnought (1906) is laid down in the United Kingdom, revolutionizing battleship design and triggering a naval arms race.
October 5 – The Wright brothers' third aeroplane (Wright Flyer III) stays in the air for 39 minutes with Wilbur piloting, the first aeroplane flight lasting over half an hour.
October 11 – The Institute of Musical Art, predecessor of the Juilliard School, opens in New York City.
October 13 – Annie Kenney and Christabel Pankhurst interrupt a Liberal Party (UK) rally at the Free Trade Hall in Manchester, England, and choose imprisonment when convicted, the first militant action of the suffragette campaign.
October 14 – The National League's New York Giants win baseball's World Series, beating the American League's Philadelphia Athletics, 2-0, in Game 5.
October 16 – The Partition of Bengal is made by Lord Curzon to separate the region of Bengal into Muslim and Hindu territories until its reunification in 1911.
October 26 – Sweden–Norway agrees to the repeal of the union with Norway, forming the two modern-day countries.
October 29 (October 16 O.S.) – In the Russian Empire:
Russian Revolution of 1905: The Imperial Russian Army opens fire on a meeting at a street market in Tallinn, Governorate of Estonia, killing 94 and injuring over 200 people.
The Circum-Baikal Railway is brought into permanent operation, completing through rail communication on the Trans-Siberian Railway.
October 30 (October 17 Old Style) – October Manifesto: Tsar Nicholas II of Russia is forced to announce the granting of his country's first constitution (the Russian Constitution of 1906), conceding a national assembly (State Duma) with limited powers.
October – Fauvist artists, led by Henri Matisse and André Derain, first exhibit their works, at the Salon d'Automne in Paris.