| 25 September 1066 | England [wars] | Harald Hardrada, King of Norway and Earl Tostig are defeated and killed by King Harold Godwinson of England at Stamford Bridge, England. Harald of Norway is succeeded by his sons Magnus II and Olaf III. |
| 25 September 1396 | Ottoman Empire, Hungary, Bulgaria [wars] | The Ottoman Turks destroy the crusading army of King Sigismund of Hungary and his western allies at Nicopolis, Bulgaria. |
| 25 September 1506 | Spain [political events] | When King Philip I ‘the Handsome’ of Castile dies suddenly in Burgos, Spain, his widow, Joanna ‘the Mad’, is forced into a confinement (on the basis of her insanity) that is to last until her death in 1555. The Castilian aristocracy, still hostile to King Ferdinand II of Aragon, appoints Cardinal Ximénez as regent. |
| 25 September 1513 | Spain, Central America, Pacific [exploration] | The members of a Spanish expedition under Vasco Núñez Balboa, governor of Darién (the Panama isthmus), are the first Europeans to sight the Pacific Ocean; on reaching the western shore of present-day Panama, they claim it for Spain. |
| 25 September 1555 | Holy Roman Empire [political events] | The Diet (legislative assembly) of Augsburg promulgates the religious Peace of Augsburg. The religious affiliations of Germany are to be decided on the principle of Curia Regis: the population must follow the religion of their ruler, or emigrate. Citizens of imperial free cities are granted freedom of conscience, as are knights, towns, and clerical territories Protestant before 2 August 1552. Any bishops subsequently converting must abandon their lands. Though none of this applies to Protestants other than Lutherans, and though it is intended as a provisional settlement, it endures until 1618. |
| 25 September 1629 | Sweden, Poland [treaties] | The Truce of Altmark is signed between Sweden and Poland. By its terms, Sweden retains Livonia, Memel, Pillau, Braunsberg, and Elbing (modern Elbla¸g, Poland). Danzig (Gdansk) is to pay two-thirds of the customs duties levied in its port to Sweden. |
| 25 September 1643 | UK [religion] | The Assembly of Westminster, summoned by the Long Parliament in England, adopts the Solemn League and Covenant, which inaugurates a Presbyterian establishment for England and Scotland. |
| 25–27 September 1799 | France, Russia, Swiss Confederation, Austria-HM [French Revolutionary Wars (1792–1801)] | French forces under General André Masséna defeat a Russian army under Alexander Korsakov at Zürich, Switzerland; the main Russian force under Field Marshal Count Alexander Vasilyevich Suvorov arrives too late, and is forced to retreat across the Alps. Austrian forces under the Archduke Charles retreat to the River Danube. |
| 25 September 1897 | USA [births and deaths] | William Faulkner, US novelist, author of a series of novels known as the Yoknapatawpha cycle and winner of the Nobel Prize for Literature in 1949, born in New Albany, Mississippi (–1962). |
| 25 September 1906 | [births and deaths] | Dmitry Shostakovich, Russian composer, born in St Petersburg, Russia (–1975). |
| 25 September–15 October 1915 | France [World War I (1914–18)] | At the Third Battle of Artois, French forces attack the German line in northeastern France and in Champagne to the southeast, while a British force, using gas for the first time, attacks the line at Loos on 4 November. Only small gains are made. |
| 25 September 1940 | Norway [World War II (1939–45)] | King Haakon of Norway is deposed, and Vidkun Quisling, leader of the Norwegian Nazi Party, is appointed prime minister by the German Reichscommissioner in Norway. |
| 25 September 1959 | Ceylon [terrorism] | Following the assassination of Solomon Bandaranaike, prime minister of Ceylon (Sri Lanka), by a Buddhist monk, he is succeeded by Wijayananda Dahanayake. |
| 25 September 1988 | USA [Protestantism] | Barbara Harris, a divorcée, is elected the first female bishop in the Anglican communion, to serve as suffragan bishop of Massachusetts. She is consecrated on 11 February 1989. |
| 25 September 1992 | USA [social legislation] | A court in Orlando, Florida allows a 12-year-old boy to divorce his parents, permitting him to be adopted by his foster parents as he wishes. His natural parents had demanded custody. |
