Births on April 23

Tony Miles, English chess player (d. 2001)

Anthony John Miles (23 April 1955 – 12 November 2001) was an English chess player and the first Englishman to earn the Grandmaster title.

7 Jan

Metropolitan Opera
Contralto Marian Anderson becomes the first person of color to perform at the Metropolitan Opera in Giuseppe Verdi's Un ballo in maschera.
13 Feb

Dead Sea Scrolls
Israel obtains four of the seven Dead Sea Scrolls.
18 Feb

Nevada Test Site
Operation Teapot: Teapot test shot "Wasp" is successfully detonated at the Nevada Test Site with a yield of 1.2 kilotons. Wasp is the first of fourteen shots in the Teapot series.
14 May

Warsaw Pact
Cold War: Eight Communist bloc countries, including the Soviet Union, sign a mutual defense treaty called the Warsaw Pact.
23 Oct

State of Vietnam referendum, 1955
Prime Minister Ngô Đình Diệm defeats former emperor Bảo Đại in a referendum and founds the Republic of Vietnam.