21 May History
- 996 - Sixteen year old Otto III is crowned the Roman Emperor.
- 1471 - King Henry VI is killed in the Tower of London. Edward IV takes the throne.
- 1506 - Christopher Columbus dies.
- 1536 - The Reformation is officially adopted in Geneva, Switzerland.
- 1620 - Present-day Martha's Vineyard is first sighted by Captain Bartholomew Gosnold.
- 1790 - Paris is divided into 48 zones.
- 1832 - The Democratic party holds its first national convention.
- 1856 - Lawrence, Kansas is captured and sacked by pro-slavery forces.
- 1863 - The siege of the Confederate Port Hudson, Louisiana, begins.
- 1881 - The American Red Cross is founded by Clara Barton.
- 1927 - Charles Lindbergh lands in Paris completing the first solo air crossing of the Atlantic.
- 1940 - British forces attack German General Rommel's 7th Panzer Division at Arras, slowing his blitzkrieg of France.
- 1941 - The first U.S. ship, the S.S. Robin Moor, is sunk by a U-boat.
- 1951 - The U.S. Eighth Army counterattacks to drive the Communist Chinese and North Koreans out of South Korea.
- 1961 - Governor Patterson declares martial law in Montgomery, Alabama.
- 1970 - The U.S. National Guard mobilizes to quell disturbances at Ohio State University.
- 1991 - In Madras, India, a suicide bomber kills the former Prime Minister, Rajiv Gandhi.
21 May Birthdays
- 427 BC - Plato, Greek philosopher.
- 1527 - Philip II, king of Spain and Portugal.
- 1844 - Henri Rousseau, French painter.
- 1856 - Grace Hoadley Dodge, philanthropist, helped organize the YWCA.
- 1860 - Willem Einthoven, physiologist, inventor of the electrocardiogram.
- 1867 - Frances Densmore, ethnomusicologist.
- 1878 - Glenn Hammond Curtiss, aviation pioneer.
- 1898 - Armand Hammer, American entrepeneur and industrialist.
- 1902 - Marcel Breuer, Hungarian-born architect.
- 1909 - Sister Maria Innocentia Hummel, artist.
- 1917 - Raymond Burr, actor (Perry Mason).
- 1921 - Andrei Sakharov, Russian physicist.
- 1926 - Robert Creeley, poet.
- 1944 - Mary Bourke Robinson, first woman president of Ireland (1990-1997).