17 May History
- 1540 - Afgan chief Sher Khan defeats Mongul Emperor Humayun at Kanauj.
- 1630 - Italian Jesuit Niccolo Zucchi sees the belts on Jupiter's surface.
- 1681 - Louis XIV sends and expedition to aid James II in Ireland. As a result, England declares war on France.
- 1756 - Britain declares war on France.
- 1792 - Merchants form the New York Stock Exchange at 70 Wall Street.
- 1814 - Denmark cedes Norway to Sweden.
- 1863 - Union General Ulysses Grant continues his push towards Vicksburg at the Battle of the Big Black River Bridge.
- 1875 - The first Kentucky Derby is run in Louisville.
- 1881 - Frederick Douglass is appointed recorder of deeds for Washington, D.C.
- 1940 - Germany occupies Brussels, Belgium and begins the invasion of France.
- 1954 - The U.S. Supreme Court unanimously rules for school integration in Brown v. Board of Education.
- 1973 - The Senate Watergate Committee begins its hearings.
17 May Birthdays
- 1444 - Sandro Botticelli, painter (The Birth of Venus).
- 1749 - Edward Jenner, physician.
- 1836 - Joseph Norman Lockyer, British astonomer, discovered helium.
- 1866 - Erik Alfred Leslie Satie, French composer.
- 1900 - Ayatollah Ruhollah Khomeini, Iranian religious leader.
- 1903 - James "Cool Papa" Bell, baseball player.
- 1912 - Archibald Cox, special prosecutor in the Watergate hearings, fired by President Nixon.