| 23 March 984 | Germany, Holy Roman Empire [political events] | Henry the Wrangler, the former Duke of Bavaria, proclaims himself king of Germany, but the Saxons and many others oppose him. |
| 23 March 1324 | Holy Roman Empire [political events] | Pope John XXII excommunicates King Ludwig IV of Bavaria for his refusal to surrender the kingship of the Romans. |
| 23 March 1369 | Spain [wars] | Henry of Trastamare kills Pedro I, former king of Castile, and becomes King Henry II in uncontested control of the kingdom. This places the Castilian fleet in the hands of an ally of France. |
| 23 March 1568 | France [treaties] | The Treaty of Longjumeau, signed by Louis de Bourbon, Prince of Condé, against the advice of his fellow Huguenot (French Protestant) Admiral Gaspard de Coligny, ends the Second War of Religion in France; confirming the concessions of the 1563 Treaty of Amboise, it effects no more than a truce; King Charles IX pays off the German Protestant forces employed by the Huguenots. |
| 23 March 1775 | England [births and deaths] | J(oseph) M(allord) W(illiam) Turner, English Romantic landscape painter, born in London, England (–1851). |
| 23 March 1801 | Russian Empire [political events] | Tsar Paul I of Russia is assassinated by military officers concerned by his dangerous mental instability. He is succeeded by his son, Alexander I. |
| 23 March 1833 | Prussia, Austrian Empire [business and economics] | Prussia establishes a Zollverein (customs union) in Germany, incorporating Bavaria, Hesse-Darmstadt, and Württemberg, from which Austria is excluded. |
| 23 March 1849 | Austrian Empire, Sardinia-Piedmont [wars] | The Austrian army of Count Joseph Radetzky decisively defeats the Piedmontese army of King Charles Albert at Novara, Piedmont, ending the war between them. Charles Albert, who had renewed the war only because of radical pressure, abdicates in favour of his son Victor Emmanuel II. |
| 23 March 1912 | [births and deaths] | Werner von Braun, German rocket engineer who was also involved in the exploration of space in Germany and the USA, born in Wirsitz, Germany (–1977). |
| 23 March 1919 | Italy [political parties] | Benito Mussolini founds the Fasci d'Italiani di Combattimento, an Italian fascist movement. |
| 23 March 1933 | Germany [administration] | An enabling bill is passed by the Nazi-dominated Reichstag (parliament) in Germany giving the chancellor, Adolf Hitler, full dictatorial powers. |
| 23 March 1977 | UK [law and government] | The British Labour prime minister James Callaghan and the Liberal leader David Steel agree on a pact between their parties (the ‘Lib–Lab Pact’) to avoid defeat in a confidence motion. |
| 23 March 1983 | USA [weapons] | The US president Ronald Reagan proposes a ‘Star Wars’ defence system for the USA, using satellites to detect and destroy incoming missiles. |
| 23 March 1987 | Japan, UK [companies and organizations] | The Japanese electronics company Sony introduces the DAT (Digital Audio Tape) recorder in the British market for professional use. |
| 23 March 1997 | world, USA [astronomy] | The comet Hale-Bopp comes to within 190 million km/120 million mi of Earth, the closest since 2000 BC. NASA launches rockets to study the comet. Its icy nucleus is estimated to be 40 km/25 mi wide, making it at least ten times larger than that of the comet Hyakutake and twice the size of Halley's Comet. |
| 23 March 2001 | [space exploration] | After 15 years in space (many more than originally planned), Russia's Mir orbital station is deliberately crashed into the Pacific Ocean, disintegrating as it passes through the Earth's atmosphere. |
| 23–31 March 2007 | Iran Iraq [diplomacy] | A serious dispute erupts between the UK and Iran as 15 British sailors and marines conducting routine anti-smuggling patrols around the Iraqi coast are seized by the Iranian navy for allegedly straying into Iranian territorial waters in the Shatt-al-Arab waterway. The British government denounces Iran's claims and its refusal to release the captives. |
