| 15 April 73 | Palestine-Roman [revolution] | Herod the Great's fortress of Masada in Judea, Palestine, occupied by Jewish extremists, is taken by the Romans under Flavius Silva after a two-year siege. |
| 15 April 1191 | Holy Roman Empire, Italy, Sicily [administration] | Pope Celestine III crowns Henry VI as Holy Roman Emperor following the death of his father Frederick I Barbarossa on 10 October 1190. Henry then begins his conquest of his wife's kingdom of Sicily, held by Tancred, Count of Lecce. |
| 15 April 1684 | Russia [births and deaths] | Catherine I (original name Marta Skowronska), ruling empress of Russia 1725–27, wife of Peter I the Great of Russia, born (–1727). |
| 15 April 1689 | Spain, France [War of the League of Augsburg (1688–97)] | King Louis XIV of France declares war on Spain, opening up another theatre of warfare in Europe. |
| 15 April 1699 | India, Mogul Empire [religion] | The tenth and last Sikh Guru Gobind Singh forms the Sikh people into Khalsa Panth. The organization is the foundation of modern Sikhism. |
| 15 April 1843 | USA, UK [births and deaths] | Henry James, US-born British novelist and playwright, born in New York City (–1916). |
| 15 April 1865 | USA [births and deaths] | Abraham Lincoln, 16th president of the USA 1861–65, a Republican, dies in Washington, DC, and is succeeded by Vice-President Andrew Johnson (56). |
| 15 April 1888 | France [elections] | Following election to the French chamber, General Georges Boulanger begins a campaign for the revision of the constitution with the intention of making himself dictator. Charles Floquet forms a cabinet which stands until February 1889. |
| 15 April 1912 | [births and deaths] | Kim Il Sung, Korean dictator 1948–94, born near Pyongyang, Korea (now North Korea) (–1994). |
| 15 April 1935 | USA [photography] | US scientists Leopold Godowsky and Leopold Mannes announce the development of ‘Kodachrome’, the first commercially available colour film. |
| 15 April 1947 | USA [baseball] | Jackie Robinson becomes the first black American player in major league baseball since Moses Fleetwood Walker in 1884 when he plays for the Brooklyn Dodgers against the Boston Braves. Five days earlier Robinson joined the Dodgers from the Montreal Royals of the International League. |
| 15 April 1980 | France [births and deaths] | Jean-Paul Sartre, French existentialist philosopher, novelist, and playwright, dies in Paris, France (74). |
| 15 April 1986 | Libya [political events] | Bombers from US warships and bases in Britain attack targets in Libya: 100 people are killed, and one aeroplane is shot down. |
| 15 April 1989 | UK [football] | Ninety-six Liverpool fans die in a crush during the Football Association (FA) Cup semifinal against Nottingham Forest at Hillsborough, Sheffield, England. |
| 15 April 1990 | Sweden, USA [births and deaths] | Greta Garbo, Swedish-born US film star of the 1920s and 1930s, then a legendary recluse after 1941, dies in New York City (84). |
| 15 April 1996 | South Africa [law and government] | The Truth and Justice Commission, set up to investigate political crimes committed by all sides during the apartheid era, opens in Johannesburg, South Africa; it is chaired by Archbishop Desmond Tutu. |
| 15 April 1998 | Cambodia [political events] | Pol Pot, Cambodian dictator and leader of the Khmer Rouge communist Movement, who was responsible for the deaths of 1.7 million Cambodians, dies, reportedly of heart failure, in a Khmer Rouge camp near the border of Cambodia and Thailand, while attempting to escape international efforts to capture him and try him for genocide (73). |