| 0 | | Earth Day |
| 238 | | The Senate declares Decimus Caelius Calvinus Balbinus Pius & Marcus Clodius Pupienus Maximus Roman Co-Emperors (Apr 22-July 29, 238) |
| 1073 | | Election of Pope Gregory VIII - Hildebrand (1073-1085), later canonized |
| 1164 | | Frederick Barbarossa makes Guido di Crema [Anti-]Pope as "Paschal III" (1164-1168) |
| 1363 | | Battle of Canturino: The White Company defeats the Milanese |
| 1370 | | Construction of the Bastille begins in Paris |
| 1509 | | Henry VIII becomes King of England, d. 1547 |
| 1521 | | King Francis I of France declares war on Spain |
| 1526 | | First known slave revolt in what is now the US, South Carolina |
| 1529 | | Treaty of Zaragoza: Spain & Portugal divide the eastern hemisphere |
| 1676 | | Naval Battle off Etna/Agosta/Catania: Dutch-Spanish vs. French |
| 1769 | | Madame du Barry becomes King Louis XV's "official" mistress |
| 1796 | | Battle of Mondovi: Napoleon defeats the Piedmontese |
| 1809 | | Battle of Eggmuhl: The French defeat the Austrians |
| 1898 | | President McKinley orders blockade of Cuba |
| 1898 | | USS 'Nashville' captures Spanish ship 'Buena Ventura' |
| 1913 | | Balkan Wars: Montenegrans capture Scutari, Albania, from the Turks |
| 1914 | | Mexico severs diplomatic relations with the US |
| 1915 | | Second Battle of Ypres: Germany introduces poison gas |
| 1930 | | Signing of the London Naval Arms Limitation Treaty -- Learn More |
| 1944 | | Hitler & Mussolini confer at Berchtesgarten |
| 1944 | | New Guinea: U.S. Army troops land near Hollandia |
| 1945 | | 3rd Inf Div demonstrates American cultural insensitivity by blowing up the Nuremberg Stadium swastika -- Learn More |
| 1945 | | Soviet and Polish troops liberate the Sachsenhausen Concentration Camp, near Oranienburg in Brandenburg, which held many political leaders from Captive Nations and special military prisoners |
| 1952 | | First live television broadcast of an atomic bomb test and of the Senate Army-McCarthy hearings |
| 1954 | | Ticker tape parade on Broadway for the 4th Infantry Division, home from Korea |
| 1961 | | General Raoul Salan attempts an anti-Gaullist coup in Algeria |
| 1972 | | Astronauts John Young & Charles Duke take a dune buggy ride on the Moon |
| 1983 | | Soyuz T-8 returns to Earth |
| 1357 | | King Jao I of Portugal (1383-1433) |
| 1451 | | Queen Isabella I of Castile-Leon (1479-1504), patron of Columbus |
| 1515 | | Antoine de Bourbon, Duke of Vendome, King of Navarre (1555-1562). |
| 1610 | | Pietro Ottoboni - Pope Alexander VIII (1689-91) |
| 1792 | | Commo. Uriah Phillips Levy, noted Jewish US Navy officer, philanthropist, duelist, d. 1862 |
| 1818 | | Cadwallader Colden Washburn, Maj Gen, U.S., d. 1882 |
| 1823 | | Alfred Gibbs, Maj Gen, U.S., d. 1868 |
| 1827 | | William Hopkins Morris, Maj Gen, U.S.. d. 1900 |
| 1831 | | Alexander McDowell McCook, Maj Gen, U.S., of the "Fighting McCooks", d. 1903 |
| 1866 | | Hans von Seeckt, German military reformer, d. 1936 |
| 1870 | | Vladimir Ilich Ulyanov, known as "Lenin" - intellectual mass murderer, d. 1924 |
| 1904 | | J. Robert Oppenheimer, physicist, head of Manhattan Project, d. 1967 |
| 1952 | | Tamara Sergeyevna Zakharova, cosmonaut |
| 296 | | Pope St Gaius (283-296) |
| 455 | | Roman Emperor Flavius Petronius Maximus (Mar 17-May 22, 455), c. 58 |
| 536 | | Pope Agapitus I (535-36) |
| 1616 | | Miguel de Cervantes Saavedra, 69, Lepanto marine and author ("Don Quixote") |
| 1806 | | Pierre-Charles-Jean-Baptiste-Silvestre de Villeneuve, 42, French admiral who lost the big one at Trafalgar, of multiple stab wounds, ruled a suicide |
| 1854 | | Nicolás Bravo Rueda, 67, Mexican Revolutionary, general, Regent of Mexico (1822). President (1839, 1842-1843, 1846) |
| 1864 | | Bvt. Maj. Gen. Joseph G. Totten (USMA 1805), at 76, scholar and engineer |
| 1994 | | Richard M Nixon, sometime naval officer, President (1969-1974), stroke at 81 |
| 2004 | | Patrick Daniel Tillman, 27, 2000 NFL All-Pro, US Army Ranger, 2002-2004, kia Afghanistan |