Event of Interest
Apr 1 Lillian Hellman's "Watch on the Rhine" premieres in NYC

Lillian Hellman
- Apr 1 US Navy takes over Treasure Island in San Francisco Bay
Event of Interest
Apr 3 British Prime Minister Winston Churchill warns Soviet leader Joseph Stalin that a German invasion is imminent

Winston Churchill

Joseph Stalin
US Masters Golf
Apr 6 8th US Masters Tournament, Augusta National GC: Craig Wood wins his first major title, 3 strokes ahead of runner-up Byron Nelson; Masters' first wire-to-wire champion

Byron Nelson
- Apr 6 Beginning of operation Bestrafung - German bombers attack Belgrade (17,000 die)
- Apr 6 British major general Michael Gambier-Parry captured in North Africa
- Apr 6 German bombardment of Piraeus (munitions ship explodes)
- Apr 6 Italian forces holding Addis Ababa surrender to British & Ethiopian forces
- Apr 7 British generals O'Connor & Neame captured in North Africa
Event of Interest
Apr 10 Independent State of Croatia led by Ante Pavelić established as fascist German puppet state

Ante Pavelić

Event of Interest
Apr 12 Vichy-France's head of government Admiral François Darlan consults with Adolf Hitler

François Darlan

Adolf Hitler
- Apr 13 Heavy German assault on Tobruk
- Apr 13 Pact of neutrality between the USSR and Japan is signed.
- Apr 14 1st massive German raid in Paris, 3,600 Jews rounded up
- Apr 14 King Peter leaves Yugoslavia
- Apr 14 45th Boston Marathon won by Leslie Pawson in 2:30:38; his third victory in the event
- Apr 15 1st helicopter flight of 1 hr duration, Stratford, Ct
- Apr 16 Little Theater at Adelphi Strand, London closes
- Apr 17 British troop land in Iraq
- Apr 17 US Office of Price Administration forms (handled rationing)
- Apr 17 World War II: The Kingdom of Yugoslavia surrenders to Germany.
- Apr 19 Bertolt Brecht's play "Mother Courage and her Children" premieres in Zurich
- Apr 19 Bulgarian troops invade Macedonia
- Apr 19 Milk rationed in Holland
- Apr 20 100 German bombers attack Athens
- Apr 20 Dodgers start to wear liners in their caps
- Apr 21 Greece surrenders to nazi-Germany
- Apr 23 Greek Army surrenders to Germany; British RAF evacuates the Greek King George II to Egypt
- Apr 24 British army begins evacuation of Greece
- Apr 24 Dutch Prince Bernhard becomes an RAF pilot

Adolf Hitler