* 1939 – 1945, the Second Battle of the Atlantic.

Subsequent formalizations were framed as attempts to define " effective calculability " or " effective method "; those formalizations included the Gödel – Herbrand – Kleene recursive functions of 1930, 1934 and 1935, Alonzo Church's lambda calculus of 1936, Emil Post's " Formulation 1 " of 1936, and Alan Turing's Turing machines of 1936 – 7 and 1939.

* 1890 – Anthony Fokker, Dutch aviation engineer ( d. 1939 )

* 1939 – André Ouellet, French-Canadian politician

* 1852 – Ferdinand von Lindemann, German mathematician ( d. 1939 )

* 1939 – Alan Ayckbourn, English writer

* 1939 – Johnny Raper, Australian rugby league footballer

* 1939 – The 1939-40 New York World's Fair opens.

* 1939 – NBC inaugurates its regularly scheduled television service in New York City, broadcasting President Franklin D. Roosevelt's N. Y. World's Fair opening day ceremonial address.

* 1939 – First flight of the turbojet-powered Heinkel He 178, the world's first jet aircraft.

* 1939 – William Least Heat-Moon, American author

* 1939 – Edward Patten, American singer-songwriter and producer ( Gladys Knight & the Pips ) ( d. 2005 )

* 1939 – Bulle Ogier, French actress

* 1939 – Romano Prodi, Italian politician and statesman

* 1939 – Hércules Brito Ruas, Brazilian footballer

* 1939 – Albert Einstein and Leó Szilárd write a letter to Franklin D. Roosevelt, urging him to begin the Manhattan Project to develop a nuclear weapon.

* 1939 – Benjamin Barber, American theorist

* 1939 – Wes Craven, American director

* 1939 – John W. Snow, American politician, 73rd United States Secretary of the Treasury

* 1984 – Marvin Gaye, American singer ( The Moonglows ) ( b. 1939 )

* 2001 – Trinh Cong Son, Vietnamese composer ( b. 1939 )

Eastern European theorists include Pyotr Stolypin ( 1862 – 1911 ) and Alexander Chayanov ( 1888 – 1939 ) in Russia ; Adolph Wagner ( 1835 – 1917 ), and Karl Oldenberg in Germany, and Bolesław Limanowski ( 1835 – 1935 ) in Poland.

* Karl-Heinz Schnellinger ( born 1939 ), football player

Auschwitz had for a long time been a German name for Oświęcim, the town by and around which the camps were located ; the name " Auschwitz " was made the official name again by the Germans after they invaded Poland in September 1939.

It seems rarely to have been used in the German military press before 1939.

Entitled Die Deutsche Kriegsstärke ( German War Strength ), it was published in Paris in 1939.

Despite the term blitzkrieg being coined by journalists during the Invasion of Poland of 1939, historians Mathew Cooper and J. P Harris generally hold that German operations during it were more consistent with more traditional methods.

The origins of blitzkrieg are in some doubt: if it existed, who contributed to it, whether it was part of German war strategy in 1933 – 1939.

Many historians now hold the position that blitzkrieg was not a military theory, and the campaigns conducted by the German military in 1939 to circa, 1942 ( with the exception of Operation Barbarossa ) were improvised invasions put together and modified at the last moment and therefore was not a proper military strategy.

Writing on Doctrine and Training in the German Army 1919 – 1939, O ’ Neill stated:

Richard Overy pointed out some 23 percent of German output was military by 1939.

During the First World War the German army used horses for logistics, 1. 4 million of them, in the 1939 – 45 war it used 2. 7 million horses.

( 1999 ) The Path to Blitzkrieg: Doctrine and Training in the German Army, 1920 – 1939.

The Second World War broke out in 1939 with the German invasion of Poland.

Relations further deteriorated when, in January 1948, the U. S. State Department also published a collection of documents titled Nazi-Soviet Relations, 1939 – 1941: Documents from the Archives of The German Foreign Office, which contained documents recovered from the Foreign Office of Nazi Germany revealing Soviet conversations with Germany regarding the Molotov-Ribbentrop Pact, including its secret protocol dividing eastern Europe, the 1939 German-Soviet Commercial Agreement, and discussions of the Soviet Union potentially becoming the fourth Axis Power.

A popular myth is that Polish cavalry armed with lances charged German tanks during the September 1939 campaign.

Image: Polish cavalry in Sochaczew ( 1939 ) a. jpg | Polish cavalry galloping through a bombed town during the German invasion of Poland in 1939.

* 1939 – World War II: Battle of the River Plate – Captain Hans Langsdorff of the German Deutschland class cruiser ( pocket battleship ) Admiral Graf Spee engages with Royal Navy cruisers HMS Exeter, HMS Ajax and HMNZS Achilles.

The Holocaust: Nazi Germany | Nazi German extermination and concentration camps in Occupation of Poland ( 1939 – 1945 ) | occupied Poland.

Most Holocaust historians identify six German Nazi extermination camps, all in occupied Poland ; two of them, Chełmno and the Auschwitz II, in the western Polish areas annexed by Nazi Germany ( October 1939 ), four in the General Government area.

* Richard von Mises, Probability, Statistics, and Truth, 1939 ( German original 1928 )

* 1939 – Gerd Bohnsack, German football manager

* 1939 – Beate Klarsfeld, German Nazi hunter

The city and seaport were occupied in September 1939 by German troops and renamed Gotenhafen after the Goths, an ancient Germanic tribe, who had lived in the area.

The German Nazi invasion of 1939 put an end to it.