| 25 October 1047 | Norway, Denmark [political events] | Magnus the Good, King of Denmark and Norway, dies. He is succeeded in Denmark by Svein II Estrithson and in Norway by Harald Hardrada. |
| 25 October 1147 | Seljuk Sultanate of Rum [Crusades (1095–1272)] | Conrad III Hohenstaufen, king of the Germans' crusading army, is heavily defeated by the Seljuk Turks on the River Bathys, near Dorylaeum in Anatolia (modern Turkey). |
| 25 October 1241 | Italy [administration] | Goffredo Castiglione is elected Pope Celestine IV. |
| 25 October 1400 | England [births and deaths] | Geoffrey Chaucer, the principal English writer before Shakespeare, whose best-known work is The Canterbury Tales (1390s), dies in London, England (c. 58). |
| 25 October 1415 | England, France [Hundred Years War (1337–1453)] | King Henry V of England inflicts a crushing defeat on the French at the Battle of Agincourt. |
| 25–27 October 1595 | Ottoman Empire, Wallachia, Transylvania, Habsburg Monarchy [Habsburg–Ottoman Wars (1525–1718)] | The allied forces of Sigismund Báthory and Michael the Brave, Princes of Transylvania and Wallachia, destroy the Ottoman army in Wallachia at Giurgiu, on the River Danube, and expel them from the province. Their Habsburg imperial allies capture the fortress of Gran (Esztergom) in Hungary. |
| 25 October 1743 | France, Spain, UK, Sardinia, Milan, Italy, Parma [treaties] | The Treaty of Fontainebleau (the ‘Second Family Compact’) between France and Spain is established. Gibraltar and Port Mahón, Minorca, are to be wrested from Great Britain; King Charles Emmanuel III of Sardinia is to surrender his recent acquisitions in Italy; and the Italian duchies of Milan, Parma, and Piacenza are to pass to Don Philip, the second son of King Philip V of Spain and Elizabeth Farnese. |
| 25 October 1825 | Austria [births and deaths] | Johann Strauss, Austrian composer of Viennese waltzes and operettas, born in Vienna, Austria (–1899). |
| 25 October 1825 | USA [canals] | The canal boat Seneca Chief opens the Erie Canal. Linking the Great Lakes with the Hudson River, it opens the Midwest to settlement. |
| 25 October 1854 | Russian Empire, UK, France [political events] | British and French forces win a narrow victory over Russia at great cost at Balaclava in the Crimea, following cavalry charges of the British Light and Heavy Brigades. |
| 25 October 1874 | UK, Pacific [colonies and mandate] | Britain annexes the Fiji islands in the southwest Pacific Ocean. |
| 25 October 1881 | Spain [births and deaths] | Pablo Picasso, Spanish painter and sculptor who, along with Georges Braque, founds cubism, born in Málaga, Spain (–1973). |
| 25 October 1924 | UK, USSR [political events] | The British newspaper the Daily Mail publishes the ‘Zinovyev Letter’, a document inciting revolutionary activity in the army and Ireland, which is said to be from Grigory Zinovyev, chairman of the External Committee of the Comintern (the Soviet-controlled Communist International). It is later proved to be a forgery. |
| 25 October 1954 | USA [television] | A meeting of the US cabinet is televised for first time. |
| 25 October 1967 | UK [legislation] | The Abortion Bill is passed in Britain, permitting abortion on medical and psychological grounds. |
| 25 October 1971 | China, Taiwan [political events] | The United Nations General Assembly votes to admit communist China (the People's Republic of China) and expel Taiwan (the Republic of China). |
| 25 October 1976 | South Africa [political events] | The black homeland of Transkei, South Africa, becomes nominally independent. |
| 25 October 1983 | Grenada [political events] | US marines invade Grenada to depose the new military government. On 28 October, the USA vetoes a United Nations (UN) resolution deploring the invasion. |
| 25 October 2001 | [business and economics] | Microsoft, the world's largest software company, launches Windows XP, a new version of its dominant computer operating system. |
