1910 | 1911 | 1912 | 1913 | 1914 | 1915 | 1916 | 1917 | 1918 | 1919
1920 | 1921 | 1922 | 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929
1930 | 1931 | 1932 | 1933 | 1934 | 1935 | 1936 | 1937 | 1938 | 1939
1940 | 1941 | 1942 | 1943 | 1944 | 1945 | 1946 | 1947 | 1948 | 1949
1 Jan 1920
- Andrew McNaughton was promoted to the rank of lieutenant-colonel.
» In-depth article
Byelorussia
- The Byelorussian Communist Organization was founded as a separate party.
Photo(s) dated 1 Jan 1920
6 Jan 1920
- USS Arizona departed New York Navy Yard, New York, United States for Guantánamo Bay Naval Base, Cuba.
» In-depth article
10 Jan 1920
- Georg von Bismarck was transferred to the German 5th Infantry Regiment.
» In-depth article
14 Jan 1920
- In Siberia, Russia, one of Semenov's armoured trains opened fire at night on a American troop train at Verkhne Udinsk; the Americans then captured the armoured train and arrested seven Cossack officers and forty-eight men, who confessed under interrogation that they had murdered fifty civilians over the past few days.
19 Jan 1920
United States
- The United States Senate voted against joining the League of Nations.
21 Jan 1920
- USS R-5 joined the US Navy winter exercises in the Gulf of Mexico.
» In-depth article
France
- The Paris Peace Conference ended.
Photo(s) dated 21 Jan 1920
23 Jan 1920
- The Americans commenced their withdrawal from Siberia, Russia; turning over their Cossack prisoners to the Czechs, but the latter were forced to release them under the threat of action by the Japanese.
1 Feb 1920
- The South African air arm was created out of a squadron (1. The Suid Afrikaanse Lugmag) that had been attached to the Royal Flying Corps during the Great War.
4 Feb 1920
- Pierre van Ryneveld and Quintin Brand departed England on a flight to South Africa.
» In-depth article
Photo(s) dated 4 Feb 1920
5 Feb 1920
United Kingdom
- The world's first Military Air Academy was established at RAF Cranwell, Lincolnshire, England, United Kingdom to train officer cadets for the British Royal Air Force.
7 Feb 1920
- Vice-Admiral Aleksandr Vasilevitch Kolchak, one-time Supreme Ruler of Russia, was taken from his cell to a place on the bank of the Angara River in Siberia, and there with Victor Pepelyaev, was shot by an execution squad and his body pushed through a hole in the ice. Representatives of the Czech Legion signed an agreement with Smirnov guaranteeing the evacuation of all Czech personnel and their equipment from Russian soil, in return for their non-intervention of the Bolshevik treatment of Kolchak and his staff.
21 Feb 1920
United States
24 Feb 1920
- Adolf Hitler made the Twenty-Five Theses speech in Munich, Germany.
» In-depth article
1 Apr 1920
- The German Workers Party (DAP) was officially renamed the National Socialist German Workers’ Party (NSDAP).
- The last American ground troops sailed from Vladivostock, Russia to the considerable relief of the State Department, leaving only units of the US Navy in the harbour.
14 Apr 1920
- USS R-5 completed the US Navy winter exercises in the Gulf of Mexico.
» In-depth article
24 Apr 1920
- Marshal Pilsudski, the Polish leader, signed a treaty with Simon Petlyura promising Ukrainian independence in return for military help in crushing the Bolsheviks.
25 Apr 1920
- Four Polish armies under the command of Marshal Pilsudski marched into the Ukraine.
28 Apr 1920
Azerbaijan
- The Azerbaijan Soviet Socialist Republic was formed.
Japan
- Crown Prince Euimin of Korea married Japanese Princess Masako of Nashimoto.
» In-depth article
Photo(s) dated 28 Apr 1920
1 May 1920
- USS Arizona arrived at New York City, New York, United States.
» In-depth article
2 May 1920
Photo(s) dated 2 May 1920
7 May 1920
- Pilsudski's Polish troops occupied Kiev, Ukraine.
- Quintin Brand received the title of Qualified Flight Instructor with the RAF Flying Training School.
» In-depth article
10 May 1920
United Kingdom
- Carrier Eagle held taxiing trials with Sopwith Camel fighters and Parnall Panther reconnaissance aircraft while still being docked.
» In-depth article
11 May 1920
United Kingdom
- Oswald Mosley married Lady Cynthia Curzon, the daughter of British Foreign Secretary George Curzon, at St James's Palace in London, England, United Kingdom. Their guests included King George V of the United Kingdom and King Leopold III of Belgium.
» In-depth article
Photo(s) dated 11 May 1920
14 May 1920
- Quintin Brand was made Knight Commander of the Order of the British Empire.
» In-depth article
15 May 1920
- Battlecruiser HMS Hood was commissioned with Captain W. Tomkinson in command.
» In-depth article
- The Bolsheviks struck back at the Polish forces with a rapid thrust in the Potock area in Ukraine.
18 May 1920
United States
24 May 1920
China
- Isaburo Yamagata succeeded Gonsuke Hayashi as the Governor-General of Kwantung Leased Territory in northeastern China.
25 May 1920
- The Bolsheviks launched a general offensive all along the front in Ukraine. The treaty with Ukrainian leader Petlyura quickly proved worthless and the Poles, outflanked by the Red Armies, were forced to retreat.
1 Jun 1920
United Kingdom
4 Jun 1920
- The US Army Reorganization Act made the Air Service a combatant arm of the army, with 1,516 officers and 16,000 men in a total force of 280,000; this legislation defeated hopes for an independent air arm similar to the RAF, but marked progress towards recognising aviation as an asset to be administered independently from ground forces; of the authorised strength, only 919 officers and 8,725 men were engaged.
8 Jun 1920
- The highest scoring Allied fighter ace of World War II, Ivan Kozhedub, was born at the village of Obrazheyevska in the Sumy region of the Ukraine.
10 Jun 1920
- Kiev, Ukraine was evacuated by the Polish forces and the Bolsheviks marched in.
- In Warsaw the Polish cabinet collapsed causing political turmoil and widespread panic; it would be two weeks before a new government was formed. Some factions pressed for peace negotiations with the Bolsheviks, but Pilsudski clung to the hope that the western Allies would come to Poland's assistance.
15 Jun 1920
- A new border treaty between Germany and Denmark gave northern Schleswig to Denmark.
16 Jun 1920
France
- Jean de Lattre de Tassigny was made a Officier of the Ordre national de la Légion d'honneur.
» In-depth article
25 Jun 1920
- USS Arizona arrived at New York City, New York, United States.
» In-depth article
30 Jun 1920
United States
6 Jul 1920
- Franklin Roosevelt was nominated as a candidate for US Vice President.
» In-depth article
7 Jul 1920
Estonia
- Finland recognized the Republic of Estonia.
17 Jul 1920
- USS Arizona was given the designation BB-39.
» In-depth article
- The Bolsheviks crossed into Polish territory and began their advance on Warsaw.
United States
23 Jul 1920
French Syria and Lebanon
- A French army under Henri Gourmand defeated the army of King Faisal's Independent Kingdom of Syria at Maysalun Pass about 12 miles west of Damascus.
25 Jul 1920
Russia
- Semyon Timoshenko was awarded the Order of the Red Banner for the first time.
» In-depth article
1 Aug 1920
Poland
- Mikhail Tukhachevsky's Bolshevik offensive drove Józef Pilsudski's Polish Army out of Brest-Litovsk, Poland (now Brest, Belarus).
2 Aug 1920
France
Poland
- Józef Pilsudski's Polish Army withdrew to Warsaw, Poland. Meanwhile Mikhail Tukhachevsky announced his intention that the Red Army would occupy the Polish capital on 12 Aug 1920.
6 Aug 1920
Kazakhstan
- The Kirghiz Autonomous Soviet Socialist Republic was formed within Russia.
Poland
- Józef Pilsudski issued his orders for the battle to defend Warsaw, Poland to be carried out on 17 Aug 1920.
8 Aug 1920
Poland
- Having captured Józef Pilsudski's plans from the body of a dead Polish officer, Mikhail Tukhachevsky (who regarded them as a hoax) issued his orders for the attack on Warsaw, Poland to be carried out on 14 Aug 1920, three days before Pilsudski planned to be ready.
11 Aug 1920
United States
- Henry Arnold was promoted to the permanent rank of major and was transferred to the US Army Air Service by the US War Department Special Order No. 188-0.
» In-depth article
16 Aug 1920
- Polish Marshal Pilsudski launched a counter offensive in the Deblin sector in Poland. Every available Polish aircraft was thrown into action in support of the ground troops. Under the combined air-ground onslaught the Red fprces wavered and broke.
Korea
- Lieutenant General Jiro Oba was named the commanding officer of the Japanese Chosen Army in occupied Korea, relieving Heitaro Utsunomiya.
17 Aug 1920
- Peace talks commenced between the Poles and Bolsheviks at Minsk, but progress slowly whilst the course of the battle remained undecided.
18 Aug 1920
Poland
- Defeated, Mikhail Tukhachevsky's 15th, 3rd and 16th Armies were in full retreat, whilst his 4th Army was trapped by a Polish counter attack from Warsaw, Poland by Józef Pilsudski's 1st, 2nd and 5th Armies.
22 Aug 1920
- The Polish spearhead reached the River Narew in eastern Poland, cutting off General Tukhachevsky's 4th Red Army from the bulk of the Soviet forces.
23 Aug 1920
- USS Arizona was named the flagship of US Navy Battleship Division 7.
» In-depth article
27 Aug 1920
- The defeated 4th Red Army, broken by the Poles at Grodno-Wolkowsysk, fled in disorder.
2 Sep 1920
- The Russo-Polish peace talk moved to Riga, Latvia as the extent of the Bolshevik military defeat became known.
13 Sep 1920
United States
- USS R-1 departed New London, Connecticut, United States for overhaul at Norfolk, Virginia, United States.
» In-depth article
- USS R-5 departed Newport, Rhode Island, United States for a scheduled overhaul at Norfolk, Virginia, United States.
» In-depth article
Photo(s) dated 13 Sep 1920
1 Oct 1920
China
- Vice Admiral Naoe Nakano succeeded Vice Admiral Tatsuo Matsumura as the commanding officer of the Ryojun Military Port (previously known as Port Arthur; now Lushunkou, Liaoning Province, China), Kwantung Leased Territory in northeastern China.
18 Oct 1920
- The Russo-Polish war was formally brought to an end with the signing of a peace treaty at Riga, Latvia.
20 Oct 1920
France
- Paul Teste landed on Béarn, becoming the first French naval aviator to make a carrier landing.
» In-depth article
2 Nov 1920
- Franklin Roosevelt was defeated as a US Vice Presidential candidate.
» In-depth article
9 Nov 1920
- Poland agreed not to enter any international agreements involving the soon-to-be-formed Free City of Danzig without Danzig's approval.
15 Nov 1920
Danzig
- The Free City of Danzig was created.
20 Nov 1920
China
- Rear Admiral Kenkichi Wada was named the chief of staff of Vice Admiral Naoe Nakano (Ryojun Military Port, northeastern China).
28 Nov 1920
Russia
- Semyon Timoshenko was awarded the honorary sword to his Order of the Red Banner.
» In-depth article
1 Dec 1920
- Chuichi Nagumo was promoted to the rank of lieutenant commander and was named the commanding officer of destroyer Momi.
» In-depth article
Japan
- Prince Hiroyasu was named a member to the Supreme War Council.
» In-depth article
Taiwan
- Admiral Naomi Taniguchi was named the commanding officer of the Mako naval port at Pescadores islands, Taiwan.
6 Dec 1920
Danzig
- Heinrich Sahm became the first President of the Senate of Danzig.
7 Dec 1920
Austria
- The Luftwaffe fighter ace Walter Nowotny was born in Gmünd, Austria. The youngest of three sons of an Austrian railway official, during the war he would be credited with no less than 258 aerial victories and commanded the world's first jet fighter wing.
Germany
20 Dec 1920
- Werner von Blomberg was promoted to the rank of Oberstleutnant.
» In-depth article
Russia
- In the Soviet Union, the foreign intelligence section of OO (Special Department) was broken out, forming the INO (Foreign Department).
31 Dec 1920
Estonia
- Poland recognized the Republic of Estonia.
Timeline Section Founder: Thomas Houlihan
Contributors: Alan Chanter, C. Peter Chen, Thomas Houlihan, David Stubblebine
Special Thanks: Rory Curtis
