| 29 December 1094 | Fatimid Caliphate [administration] | With the death of Caliph al-Munstansir the Fatimid caliphate goes into rapid decline, as the caliphate is held by a succession of powerless nonentities, several of whom are murdered. |
| 29 December 1170 | England [crime and punishment] | St Thomas à Becket, chancellor of England 1155–62, archbishop of Canterbury 1162–70, is murdered in his cathedral by four knights acting on an angry outburst by King Henry II of England, expressing his wish to be rid of ‘this turbulent priest’ (52). His tomb becomes one of the most important of all medieval pilgrimage sites. |
| 29 December 1503 | Spain, France, Naples, Italy [wars] | Spanish forces under Gonzalo de Córdoba defeat the French at the Battle of the River Garigliano, completing the Spanish conquest of the kingdom of Naples and domination of southern Italy. |
| 29 December 1552 | France [births and deaths] | Henri I de Bourbon, second Prince of Condé, French Huguenot leader, born in La Ferté-sous-Jouarre, France (–1588). |
| 29 December 1809 | England [births and deaths] | William Ewart Gladstone, prime minister of Britain 1868–74, 1880–85, 1886, and 1892–94, a Liberal, born in Liverpool, England (–1898). |
| 29 December 1845 | Republic of Texas, USA [political events] | Texas becomes a US state. |
| 29 December 1921 | Canada [political events] | Following the defeat of the Conservatives in the Canadian general election, the Liberal leader Mackenzie King is appointed prime minister and governs with support from the Progressives. |
| 29 December 1954 | North Vietnam, South Vietnam, Laos, Cambodia, France [treaties] | Vietnam, Laos, and Cambodia all become independent under a treaty with France. |
| 29 December 1981 | USA [political events] | Responding to perceived Soviet political pressure on Poland to adopt martial law, President Ronald Reagan introduces US economic sanctions against the USSR. |
| 29 December 1986 | UK [births and deaths] | Harold Macmillan, British politician, Conservative prime minister 1957–63, dies in Birch Grove, Sussex, England (92). |
| 29 December 1989 | Czechoslovakia [elections] | The former dissident Václav Havel attends a thanksgiving mass in St Vitus' Cathedral, Prague, after his inauguration as the first noncommunist president of Czechoslovakia for 41 years. |