* 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.

* Stephen Philip de László ( died 7 January 1939 ); married Edith Alexandra Diana von Versen ( died 30 December 1938 )

László Kovács () ( born 3 July 1939 in Budapest ) is a Hungarian politician and diplomat, former European Commissioner for Taxation and Customs Union.

Paepcke hired Bauhaus designer Herbert Bayer and brought him to Aspen to promote the project through poster design and other design work ; Paepcke was also the patron of fellow Bauhaus figure László Moholy-Nagy by financing the re-birth of the American New Bauhaus in Chicago in 1939. The New Bauhaus also had links to the Armour Institute of Technology.

* 1939 – Jolán Kleiber-Kontsek, Hungarian discus thrower

* 1860 – Ottó Bláthy, Hungarian engineer and inventor ( d. 1939 )

Franz Schmidt ( 22 December 187411 February 1939 ) was an Austrian composer, cellist and pianist of Hungarian descent and origin.

* 1939 – The Hungarian air force attacks the headquarters of Slovak air force in the city of Spišská Nová Ves, kills 13 people and began the Slovak – Hungarian War.

In 1939, Hungarian engineer Peter Carl Goldmark introduced an electro-mechanical system while at CBS, which contained an Iconoscope sensor.

In January 1939, the Slovak government prohibited all parties apart from the Party of Slovak National Unity and two parties of minority populations, the " German Party " and the " Unified Hungarian Party ".

Ottó Titusz Bláthy ( Tata 11 August 1860 – Budapest 26 September 1939 ) was a Hungarian electrical engineer.

The region declared its independence as Carpatho-Ukraine on March 15, 1939, but was occupied by Hungary between March 15 and March 18, 1939, remaining under Hungarian control until the German occupation of Hungary in 1944.

It declared itself an independent republic on March 15, 1939, but was occupied by Hungary between March 15 and March 18, 1939, remaining under Hungarian control until the Nazi occupation of Hungary in 1944.

The Hungarian Border Guard units stationed around Mukačevo, after throwing back the attacking Czechs on March 14, 1939, pressed forward in turn, and took the town of Orhegyalja.

On March 15, 1939 the Hungarian Army regular troops invaded Carpatho-Ukraine and by the nightfall reached Szolyva.

* István Nagy ( born 1939 ), Hungarian footballer

Koestler wrote Darkness at Noon as the second part of a trilogy: the first volume was The Gladiators ( 1939 ), first published in Hungarian.

* Esther's Inheritance ( 1939, published in English in 2008 ), Hungarian title: Eszter hagyatéka.

As from January 31, 1939 all parties except for the HSLS-SSNJ, the Deutsche Partei ( party of the German minority ) and the Unified Magyar Party ( party of the Hungarian minority ) were prohibited.

In the 1930s, Ferencváros won the Hungarian National Championship I four times ( 1931 – 32, 1933 – 34, 1931937-38, and 1939 – 40 ).

Hitler and the Hungarian delegation in 1939, Berlin: Prime Minister Count Pál Teleki, Minister of Foreign Affairs István Csáky and Hungarian Ambassador to Germany Döme Sztójay

In Florence she met the Hungarian art historian Jenö Lányi and in 1938 the couple left Italy for London, where they married on 2 March, 1939.

The party attracted a large number of followers and in the 1939 elections it gained 30 seats in the Hungarian Parliament, thus becoming one of the more powerful parties in Hungary.

The late 20's and 30's brought the first golden age of the club, marked by finishing on top of the Hungarian first division 5 times and international cup success, including two Mitropa Cup titles in 1929 and 1939, and also the Cup of Nations title in 1930.