| 20 November 855 | Byzantine Empire [political events] | The Byzantine emperor, Michael III, begins his personal rule after arranging the murder of Theoctistus the Logothete, the principal minister of his mother, the empress and regent Theodora. Michael banishes Theodora to a convent. |
| 20 November 1272 | England [political events] | Edward Plantagenet, the son of the late King Henry III, is proclaimed king of England by hereditary right. |
| 20 November 1441 | Milan, Holy Roman Empire, Italy, Venice [treaties] | By the Treaty of Cavriana (published 10 December), Milan and Venice make peace through the mediation of Francesco Sforza, the Venetian captain, who has married Bianca, daughter and heir of Filippo Maria Visconti, Duke of Milan. |
| 20 November 1656 | Sweden, Brandenburg, Holy Roman Empire, Germany [treaties] | By the Treaty of Labiau, Sweden cedes East Prussia to Frederick William, the Great Elector of Brandenburg, making him sovereign of the area. |
| 20 November 1780 | UK, United Netherlands [American Revolutionary War (1775–83)] | Britain declares war on the United Netherlands to prevent it joining the League of Armed Neutrality created by Russia on 10 March. |
| 20 November 1815 | France, Switzerland, Austrian Empire, Prussia, Russian Empire, UK [treaties] | By the Second Treaty of Paris, France's borders are reduced to those of 1789. It yields territory to Savoy and to Switzerland, and agrees to restore captured art treasures and pay an indemnity, while the Quadruple Alliance between Austria, Prussia, Russia, and Britain is renewed. |
| 20 November 1889 | USA [births and deaths] | Edwin Powell Hubble, US astronomer who provides the first proof that the universe is expanding, born in Marshfield, Missouri (–1953). |
| 20 November 1910 | [births and deaths] | Lev Nikolayevich (‘Leo’) Tolstoy, Russian author best known for War and Peace and Anna Karenina, dies in Astapovo, Russia (82). |
| 20 November–7 December 1917 | France [World War I (1914–18)] | The Battle of Cambrai takes place in northeastern France and is the first major battle involving tanks. A British tank force breaks the German line at Cambrai, but their success is not exploited. |
| 20 November 1919 | Latvia, Lithuania, Germany [political events] | German troops are forced to evacuate Latvia and Lithuania under the terms of the Treaty of Versailles. |
| 20 November 1945 | Germany [crime and punishment] | The trials of 24 leading Nazis opens before the Allied International Military Tribunal in Nuremberg, Germany. The Tribunal rules that an individual's obedience to orders is an insufficient defence for crimes committed against humanity. The trials continue until 31 August 1946. |
| 20 November 1947 | England [political events] | The wedding of Princess Elizabeth and Philip Mountbatten takes place in Westminster Abbey, London, England. |
| 20 November 1966 | USA [musicals] | The musical Cabaret, by John Kander and Fred Ebb, is first performed, at the Broadhurst Theater, New York City. |
| 20 November 1975 | Spain [births and deaths] | Francisco Franco, Spanish leader of the right-wing nationalist forces in the Spanish Civil War 1936–39, then dictator for life, dies in Madrid, Spain (82). |
| 20 November 1984 | UK [law and government] | The British government sells shares in British Telecom, for the first time using techniques of mass marketing with the intention of creating a nation of small shareholders. The share offer is four times oversubscribed. |
| 20 November 1999 | China [space exploration] | China launches its first spacecraft, an uncrewed vehicle that travels for 21 hours in space, from the Jinquan satellite centre in the northwest province of Gansu. |
| 20 November 2007 | UK [political events] | In a major privacy and security lapse, the British government admits to the loss of computer discs containing personal data on 25 million child benefit recipients in postal transit from HM Revenue and Customs to the National Audit Office. |
