Prince Charles marries Camilla Parker Bowles. Charles was formerly married to Diana, Princess of Wales. His second marriage to Camilla made him the first member of the British Royal Family to have a civil wedding.

The first Boeing 737 takes off on its maiden flight. The short-to-medium range plane is the best-selling airplane in history.

The Bolivian National Revolution overthrows Hugo Ballivián's government. The nationalist movement initiated radical reforms, including universal suffrage, the nationalization of tin mines, and the inclusion of previously marginalized ethnicities into national life.

Germany invades Denmark and Norway. The rationale of Operation Weserübung was to secure access to Swedish iron ore. In Norway, a resistance group around Max Manus and Gunnar Sønsteby successfully sabotaged the German war effort.

The world's first recording of the human voice is created. French inventor Édouard-Léon Scott de Martinville used his phonautograph, the earliest known sound recording device, to capture himself singing the French folk song “Au clair de la lune”.