30 April History
- 313 - Licinius unifies the whole of the eastern Roman Empire under his own rule.
- 1250 - King Louis IX of France is ransomed.
- 1527 - Henry VIII of England and King Francis of France sign treaty of Westminster.
- 1563 - All Jews are expelled from France by order of Charles VI.
- 1725 - Spain withdraws from the Quadruple Alliance.
- 1789 - George Washington is inaugurated as the first U.S. president.
- 1803 - The United States doubles in size through the Louisiana Purchase, which was sold by France for $15 million.
- 1812 - Louisiana is admitted into the Union as a state.
- 1849 - Giuseppe Garabaldi, the Italian patriot and guerrilla leader, repulses a French attack on Rome.
- 1864 - Work begins on the Dams along the Red River, which will allow Union General Nathaniel Banks' troops to sail over the rapids above Alexandria, Louisiana.
- 1930 - The Soviet Union proposes a military alliance with France and Great Britain.
- 1931 - The George Washington Bridge, linking New York City and New Jersey, opens.
- 1943 - The British submarine HMS Seraph drops 'the man who never was,' a dead man the British planted with false invasion plans, into the Mediterranean off the coast of Spain.
- 1945 - Adolf Hitler commits suicide in his bunker. Karl Donitz becomes his successor.
- 1968 - U.S. Marines attack a division of North Vietnamese troops in the village of Dai Do.
- 1970 - U.S. troops invade Cambodia to disrupt North Vietnamese Army base areas.
- 1972 - The North Vietnamese launch an invasion of the South.
- 1973 - Nixon announces the resignation of H.R. Haldeman, John Ehrlichman, and other top aides.
- 1975 - North Vietnamese troops enter the Independence Palace of South Vietnam in Saigon ending the Vietnam War.
- 1980 - Terrorists seize the Iranian Embassy in London.
30 April Birthdays
- 1777 - Karl Friedrich Gauss, German mathematician.
- 1858 - Mary Scott Lord Dimmick, First Lady to President Benjamin Harrison .
- 1870 - Franz Lehár, Hungarian composer (The Merry Widow, The Land of Smiles).
- 1909 - Juliana, Queen of the Netherlands.
- 1912 - Eve Arden (Eunice Quedens), actress.
- 1933 - Willie Nelson, country singer.
- 1945 - Annie Dillard, writer (Pilgrim at Tinker Creek).
- 1954 - Jane Campion, New Zealand film director (The Piano, A Portrait of a Lady).