| 23 June 964 | Italy, Holy Roman Empire [political events] | The Holy Roman Emperor, Otto I of Germany, marches on Rome, exiles Pope Benedict V the Grammarian to Hamburg, Germany, and restores Pope Leo VIII. |
| 23 June 1101 | France, Seljuk Sultanate of Rum [Crusades (1095–1272)] | A new crusading army, led from Constantinople by Raymond IV, Count of Toulouse, takes the city of Ankara from the Seljuk Turkish sultanate of Rum. |
| 23 June 1372 | France, Castile, Spain, England [Hundred Years War (1337–1453)] | In a naval battle off the coast of La Rochelle, France, King Henry II of Castile, as the ally of France, destroys an English fleet bringing John Hastings, Earl of Pembroke and lieutenant of King Edward III of England, to Gascony, France. |
| 23 June 1691 | Ottoman Empire [administration] | Ahmad II succeeds Süleyman III as sultan of the Ottoman Empire. |
| 23 June 1757 | UK, India, Mogul Empire [wars] | The English soldier and colonial administrator Robert Clive marches against Siraj ud-Daula, the nawab (ruler) of Bengal, India, and wins the Battle of Plassey. Clive installs Mir Jaffer as nawab and brings Bengal under British control. |
| 23 June 1760 | Prussia, Silesia, Germany, Austria, Habsburg Monarchy, Holy Roman Empire [Seven Years War (1754–62)] | The Prussian army under General Fouqué at Landshut, Silesia, guarding the passes into Silesia, suffers a crushing defeat at the hands of the Austrians under Baron Gideon Ernst von Laudon. |
| 23 June 1763 | France [births and deaths] | Joséphine de Beauharnais, Empress of France 1804–10 and consort of Napoleon I, born in Trois-Ilets, Martinique (–1814). |
| 23 June 1828 | Portugal [administration] | Dom Miguel is proclaimed king of Portugal, following a peaceful coup d'état. |
| 23 June 1894 | England [births and deaths] | Edward VIII, king of Great Britain and Northern Ireland (January–December 1936) who abdicates to marry the US divorcée Wallis Simpson, born in Richmond, Surrey, England (–1972). |
| 23 June 1908 | Persia [revolution] | In a Russian-backed counter-revolutionary coup, Shah Mohammed Ali overthrows the Persian constitution of December 1906. |
| 23 June 1912 | [births and deaths] | Alan Mathison Turing, English mathematician who pioneered computer theory and computer processes, born in London, England (–1954). |
| 23 June–7 July 1915 | Italy [World War I (1914–18)] | The First Battle of the Isonzo takes place when an Italian army under General Luigi Cadorna tries to force bridgeheads on the River Isonzo at Gorizia and Tolmino in Italy, an area held by Austrian forces led by Archduke Eugene. |
| 23 June 1989 | Angola [political events] | President José Eduardo dos Santos of Angola and Jonas Savimbi, leader of the UNITA rebels, sign a declaration ending the 14-year civil war in Angola. |
| 23 June 1994 | France, Rwanda [political events] | France sends troops into Rwanda to protect refugees and support the humanitarian effort, following difficulties in establishing an international force. |
| 23–24 June 2003 | China Hong Kong [plagues and epidemics] | The spread of the deadly SARS virus (severe acute respiratory syndrome) is seemingly being brought under control as the World Health Organization (WHO) lifts warnings against travel to the two previously worst affected areas of Beijing and Hong Kong in China. |
