- 1096 – The Seljuk forces of Kilij Arslan destroyed the army of thePeople's Crusade as it marched toward Nicaea.
- 1520 – The islands of Saint Pierre and Miquelon were discovered by Portuguese explorer João Álvares Fagundes, who named them "Islands of the 11,000 Virgins".
- 1805 – Napoleonic Wars: Lord Nelson signalled "England expects that every man will do his duty" to the rest of his Royal Navy forces before they defeatedPierre-Charles Villeneuve and his combined French and Spanish navy at the Battle of Trafalgar off the coast of Spain's Cape Trafalgar.
- 1959 – The Solomon R. Guggenheim Museum (pictured), designed by American architect Frank Lloyd Wright, opened in New York City.
- 1978 – After reporting contact with an unidentified aircraft, Frederick Valentichdisappeared in unexplained circumstances while piloting a Cessna 182L light aircraft over the Bass Strait to King Island, Australia.
