- Jan 30 Hitler threatens the Jews during his speech to the German Reichstag (Parliament)
- Mar 3 Mahatma Gandhi begins a fast in Mumbai (Bombay) to protest against autocratic rule in India
- Mar 17 Sino-Japanese War (1937-1945): The Battle of Nanchang between the Kuomintang and the Japanese breaks out.
- Mar 28 Spanish Civil War ends, Madrid falls to Francisco Franco
- May 7 Germany and Italy announce an alliance known as the Rome-Berlin Axis
- May 22 Adolf Hitler & Benito Mussolini sign "Pact of Steel"
- Sep 1 World War II starts as Germany invades Poland by attacking the Free City of Danzig
- Sep 3 World War II: Britain declares war on Germany after invasion of Poland. France follows 6 hours later quickly joined by Australia, New Zealand, South Africa & Canada
- Sep 14 World’s 1st practical helicopter, the VS-300 designed by Igor Sikorsky takes (tethered) flight in Stratford, Connecticut
- Sep 28 German-Soviet Frontier Treaty is signed by Joachim von Ribbentrop and Vyacheslav Molotov; redraws German and Soviet spheres of influence in central Europe and transfers most of Lithuania to the USSR
Daily newspaper comic strip "Superman" debuts
On January 16, 1939
Winston Churchill calls Russia a "riddle wrapped in a mystery inside an enigma"
On October 1, 1939