| 20 January 882 | Carolingian Empire [political events] | King Louis of Saxony and Bavaria dies and is succeeded by the Frankish emperor, Charles III the Fat of Alemannia, who thus reunites Germany. |
| 20 January 1327 | England [administration] | King Edward II of England abdicates in favour of his son Edward III. |
| 20 January 1356 | Scotland, England [Anglo–Scottish Wars 1296–1371)] | Edward Balliol abdicates as king of Scotland, selling his claim to King Edward III of England who now invades as far as Edinburgh, Scotland. |
| 20 January 1513 | Denmark-Norway, Sweden [political events] | Christian II succeeds as king of Denmark and Norway on the death of King John I. He continues his family's claim in Sweden, where Sten Sture the Younger, deposing the pro-Danish Erik Trolle with the aid of a peasant insurrection, achieves the regency held by his father Svante Sture. |
| 20 January 1613 | Sweden, Denmark-Norway, UK [wars] | The Peace of Knäred, mediated by King James I of England, ends the War of Kalmar between Denmark and Sweden; Denmark gains acknowledgement of its claim to Finnmark and retains Älvsborg for four years as security against reparations of $1 million. |
| 20 January 1649 | UK [law and government] | The trial of King Charles I of Great Britain and Ireland takes place in Westminster Hall, London, England. He is charged with levying war on Parliament and acting as a tyrant and traitor, but refuses to plead before what he regards as an illegal court. |
| 20 January 1745 | Holy Roman Empire, Bavaria, Germany, Austria, Habsburg Monarchy [War of the Austrian Succession (1740–46)] | Following the death of the Holy Roman Emperor Charles VII (Charles Albert, elector of Bavaria), his son Maximilian Joseph of Bavaria subsequently agrees to support the candidature of Grand Duke Francis Stephen, consort of Archduchess Maria Theresa of Austria, as emperor. |
| 20 January 1788 | France [political events] | The Parlement of Paris presents a list of grievances against the French government to the king, Louis XVI, in effect declaring itself the defender of French liberties. |
| 20 January 1839 | Chile, Peru, Bolivia [wars] | The Battle of Yungay, resulting in a victory for Chile against the Peru–Bolivia Federation, leads to the dissolution of the Federation. |
| 20 January 1841 | China, UK [colonization] | British sovereignty is proclaimed over the Chinese port of Hong Kong. |
| 20 January 1848 | Denmark, Germany [political events] | King Christian VIII of Denmark dies and is succeeded by his liberal son Frederick VII, who is nevertheless committed to retaining the duchies of Schleswig and Holstein despite their claims for independence. |
| 20 January 1946 | France [political events] | Charles de Gaulle resigns the presidency of the post-World War II French provisional government when he is frustrated by the parliamentary system in the implementation of his plans for post-war reconstruction. |
| 20 January 1949 | USA [administration] | Making his inaugural address, President Harry S Truman of the USA announces his Fair Deal: a liberal domestic reform programme that extends social security, raises the minimum wage, and increases public housing legislation. He also announces a four-point programme that includes economic aid for underdeveloped countries. |
| 20 January 1953 | USA [television] | Dwight D Eisenhower is inaugurated as 34th president of the USA. The ceremony is broadcast throughout the country on television for the first time. |
| 20 January 1958 | UK [motor vehicles] | Radar is first used in Britain to catch speeding drivers. |
| 20 January 1972 | USA [banking and finance] | Juanita Kreps is appointed the first woman governor of the New York stock exchange. |
| 20 January 1981 | Iran [diplomacy] | Iran releases all 52 US hostages, held since November 4, 1979, after an agreement is signed in Algiers releasing Iranian financial assets in the USA. |
| 20 January 1998 | United Arab Emirates [animal husbandry] | Veterinarians in Dubai, United Arab Emirates, announce the birth of Rama the ‘cama’, the first cross between a camel and a llama. It has the long fleece of llama but the strength of a camel; it has no hump. |
| 20 January 2001 | USA [elections] | George W Bush of the Republican Party is sworn in as the 43rd president of the USA. Outgoing president Bill Clinton leaves office with immunity from criminal prosecution for lying about his sexual liaisons with Monica Lewinsky. |
