What happened on 17 May?

12 events from the Ever-When timeline, ranked by how much they mattered.

1. 1749 Born: Edward Jenner English country doctor and pioneer of vaccination.
2. 1954 Brown v. Board of Education Supreme Court rules school segregation unconstitutional.
3. 1973 The Senate Watergate hearings open Senator Sam Ervin's committee begins televised hearings that transfix the country all summer. John Dean testifies that he warned Nixon of 'a cancer on the presidency' — and that th
4. 1805 Muhammad Ali seizes power in Egypt An Albanian Ottoman officer founds the dynasty that modernises Egypt and breaks from Istanbul's control.
5. 1995 Presidency of Jacques Chirac Nuclear tests in the Pacific, cohabitation with Jospin's government and its 35-hour week, and the refusal to join the invasion of Iraq.
6. 1866 Born: Erik Satie Eccentric French composer; pioneer of musical Minimalism.
7. 1215 The barons take London Having renounced their fealty, the rebel barons are let into London by its citizens while the loyalists are at mass — and with his capital, his mint and his exchequer in rebel hand
8. 1861 First colour photograph Maxwell demonstrates his three-colour theory at the Royal Institution by projecting a tartan ribbon photographed through red, green and blue filters.
9. 1540 Battle of Kannauj Sher Shah Suri routs Humayun on the Ganges; the second Mughal emperor flees into fifteen years of exile, much of it at the Safavid court.
10. 1642 Founding of Montreal Missionaries found Ville-Marie on an island in the St Lawrence as a utopian religious colony; the fur trade has other plans for it.
11. 1814 Norwegian constitution signed at Eidsvoll Between Danish rule and forced union with Sweden, Norway writes Europe's most liberal constitution; 17 May is still the national day it never gave up.
12. 2013 France legalises same-sex marriage After months of mass street protests, Hollande signs the Taubira law opening marriage and adoption to same-sex couples — the flagship reform of his presidency.