Births on April 20

Giles Henderson, English lawyer and academic

Giles Ian Henderson, CBE (born 20 April 1942) is a solicitor who was Master of Pembroke College, Oxford.

25 Jan

Thailand
World War II: Thailand declares war on the United States and United Kingdom.
8 Mar

Myanmar
World War II: Imperial Japanese Army forces captured Rangoon, Burma from British.
10 Jul

Soviet Union
Diplomatic relations between the Netherlands and the Soviet Union are established.
13 Aug

Manhattan Project
Major General Eugene Reybold of the U.S. Army Corps of Engineers authorizes the construction of facilities that would house the "Development of Substitute Materials" project, better known as the Manhattan Project.
25 Sep

Holocaust
World War II: Swiss Police instruction dictates that "Under current practice ... refugees on the grounds of race alone are not political refugees", effectively denying entry to Jews trying to flee occupied Europe during the Holocaust.