April 5 - The New Guinea Council of Western Papua is installed.

April 8 - The British passenger ship Dara blows up and sinks off Dubai. 238 passengers and crew are killed.

April 11 - The trial of Nazi Adolf Eichmann begins in Jerusalem.

April 12 - Vostok 1: Soviet cosmonaut Yuri Gagarin becomes the first human in space, orbiting the Earth once. - Albert Kalonji takes the title Emperor Albert I Kalonji of South Kasai.

April 13 - In Portugal, a coup attempt against António de Oliveira Salazar fails.

April 17 - The Bay of Pigs Invasion of Cuba begins; it fails by April 19. - The 33rd Academy Awards ceremony is held.

April 18 - Portugal sends to Angola its first military reinforcement.

April 20 - Fidel Castro announces that the Bay of Pigs invasion has been defeated.

April 22 - Algiers putsch: Four French generals who oppose de Gaulle's policies in Algeria fail in a coup attempt.

April 23 - Judy Garland performs in a legendary comeback concert at Carnegie Hall in New York City.

April 24 - The Swedish ship Regalskeppet Vasa is removed from the water after being sunk 333 years earlier.

April 27 - President Kennedy delivers a revealing speech: The President and the Press: Address before the American Newspaper Publishers Association - Sierra Leone becomes independent from the United Kingdom. (source: Wikipedia)