Before the war
Diplomacy 1918–1939
Selected treaties, conferences and crises from the armistice of 11 November 1918 to 31 August 1939. This is an overview, not a full chronicle: the atlas map and timeline begin in 1939, and selected relations between states in that period are in the Diplomacy view (from 11 Nov 1918).
Tertiary sources (Wikipedia). Entries without a day have an uncertain exact date. Relations on 1 Jan 1936 →
1918–1922: the peace settlement
11 November 1918 · treaty
Armistice with Germany ends the fighting of the First World War; Allied troops move to occupy the Rhineland.
18 January 1919 · conference
The Paris Peace Conference opens to negotiate treaties with the defeated powers.
2 March 1919 · politics
The Comintern (Third International) is founded in Moscow.
28 June 1919 · treaty
Germany and the Allies sign the Treaty of Versailles, imposing arms limits and reparations.
10 September 1919 · treaty
German-Austria signs the Treaty of Saint-Germain, which forbids union with Germany.
12 September 1919 · crisis · force
Gabriele D'Annunzio seizes the disputed city of Fiume.
27 November 1919 · treaty
Bulgaria signs the Treaty of Neuilly-sur-Seine, cutting its army to 20,000 men and ordering reparations.
January 1920 · League of Nations
The League of Nations is established; the United States never joins.
4 June 1920 · treaty
Hungary signs the Treaty of Trianon, defining its borders.
10 August 1920 · treaty
The Ottoman Empire signs the Treaty of Sèvres, partitioning its territory (later annulled).
October 1920 · crisis · force
Żeligowski's Mutiny: a Polish force seizes Vilnius without official state backing.
15 November 1920 · treaty
The Free City of Danzig is established under the Treaty of Versailles.
24 December 1920 · crisis · force
Italy occupies Fiume after ending D'Annunzio's resistance.
18 March 1921 · treaty
The Polish–Soviet War ends with the Peace of Riga.
25 August 1921 · treaty
The United States signs separate peace treaties with Germany and Austria (with Hungary on 29 August).
9 November 1921 · politics
Mussolini founds the National Fascist Party in Rome.
6 February 1922 · treaty
The Washington Naval Treaty is signed by the UK, US, Japan, France and Italy, limiting naval forces.
16 April 1922 · treaty
Germany and the USSR sign the Treaty of Rapallo, restoring diplomatic relations.
29 October 1922 · politics
Mussolini becomes Italian prime minister after the March on Rome.
1923–1929: reparations and Locarno
11 January 1923 · crisis · force
France and Belgium occupy the Ruhr to compel German reparations.
24 July 1923 · treaty
The Treaty of Lausanne settles the borders of modern Turkey and replaces Sèvres.
31 August 1923 · crisis · force
Italy bombards and occupies the Greek island of Corfu (Corfu incident).
27 September 1923 · conference
The Conference of Ambassadors rules for Italy; its troops withdraw from Corfu.
8 November 1923 · politics
Hitler's Beer Hall Putsch fails in Munich.
1 February 1924 · treaty
The United Kingdom extends diplomatic recognition to the Soviet Union.
16 March 1924 · crisis · force
Italy annexes the Free State of Fiume.
16 August 1924 · treaty
The Dawes Plan is accepted, ending the Ruhr occupation and setting a reparations schedule.
1 December 1925 · treaty
The Locarno Treaties are signed in London, settling western European borders (negotiated at Locarno in October).
24 April 1926 · treaty
Germany and the USSR sign the Treaty of Berlin, pledging neutrality if either is attacked.
8 September 1926 · League of Nations
Germany joins the League of Nations.
27 August 1928 · treaty
The Kellogg–Briand Pact is signed, outlawing aggressive war.
9 February 1929 · treaty
The Litvinov Protocol is signed by the USSR, Poland, Estonia, Romania and Latvia.
11 February 1929 · treaty
Italy and the Holy See sign the Lateran Treaty.
31 August 1929 · treaty
The Young Plan, setting Germany's total reparations, is finalized.
1930–1935: the system under strain
22 April 1930 · treaty
The UK, US, France, Italy and Japan sign the London Naval Treaty.
30 June 1930 · crisis · force
France withdraws its remaining troops from the Rhineland.
14 September 1930 · politics
The Nazis become the second-largest party in the Reichstag.
18 September 1931 · crisis · force
The Mukden incident gives Japan a pretext for war; Japan invades Manchuria the next day.
1 March 1932 · crisis · force
Japan creates the puppet state of Manchukuo.
25 July 1932 · treaty
The Soviet–Polish Non-Aggression Pact is signed.
30 January 1933 · politics
Hindenburg appoints Hitler Chancellor of Germany.
23 March 1933 · politics
The Reichstag passes the Enabling Act, making Hitler dictator.
27 March 1933 · League of Nations
Japan leaves the League of Nations over the Lytton Report.
2 September 1933 · treaty
Italy and the USSR sign the Italo-Soviet Pact.
19 October 1933 · League of Nations
Germany leaves the League of Nations.
16 November 1933 · treaty
The United States extends diplomatic recognition to the USSR.
26 January 1934 · treaty
Germany and Poland sign a ten-year Non-Aggression Pact.
9 February 1934 · treaty
The Balkan Pact (Greece, Turkey, Romania, Yugoslavia) is signed as a military alliance.
5 May 1934 · treaty
The Soviet–Polish pact is extended to 31 December 1945.
25 July 1934 · crisis · force
Austrian Chancellor Dollfuss is assassinated during the failed July Putsch.
2 August 1934 · politics
Hindenburg dies; Hitler becomes Führer, combining head of state and chancellor.
September 1934 · League of Nations
The Soviet Union joins the League of Nations.
9 October 1934 · crisis · force
King Alexander of Yugoslavia and French foreign minister Louis Barthou are assassinated in Marseille.
7 January 1935 · League of Nations
The League approves the Saar plebiscite, allowing the Saar's return to Germany.
18 June 1935 · treaty
The Anglo-German Naval Agreement caps German naval strength at 35% of Britain's.
31 August 1935 · politics
The US Neutrality Act imposes an arms embargo on all belligerents.
15 September 1935 · politics
The Reichstag passes the Nuremberg Laws against Jews.
3 October 1935 · crisis · force
Italy invades Ethiopia; the League condemns the attack, but sanctions fail to stop it.
1936–1938: alignments and annexations
7 March 1936 · crisis · force
Germany remilitarizes the Rhineland in violation of Versailles.
5 May 1936 · crisis · force
Italian troops enter Addis Ababa, ending the Second Italo-Abyssinian War.
18 July 1936 · crisis · force
The Spanish coup of July 1936 begins the Spanish Civil War.
25 November 1936 · treaty
Japan and Germany sign the Anti-Comintern Pact.
21 February 1937 · conference
The Non-Intervention Committee bars foreign involvement in Spain.
7 July 1937 · crisis · force
The Marco Polo Bridge incident begins the Second Sino-Japanese War.
5 October 1937 · politics
Roosevelt's Quarantine Speech calls for isolating aggressor nations.
5 November 1937 · politics
Hitler's secret Hossbach meeting discusses expansion for "living space" (Lebensraum).
6 November 1937 · treaty
Italy joins the Anti-Comintern Pact.
11 December 1937 · League of Nations
Italy leaves the League of Nations.
13 March 1938 · crisis · force
Germany annexes Austria (Anschluss).
6 July 1938 · conference
The Évian Conference (6–16 July): the US and UK refuse to admit more Jewish refugees.
30 September 1938 · treaty
The Munich Agreement lets Germany annex the Sudetenland.
9 November 1938 · politics
Nazis use the death of diplomat Ernst vom Rath to launch the Kristallnacht pogrom.
1939: the road to war (to 31 August)
15 March 1939 · crisis · force
Germany occupies and annexes Bohemia and Moravia; the Protectorate is established.
23 March 1939 · crisis · force
Germany annexes the Klaipėda (Memel) Region after an ultimatum to Lithuania on 20 March.
31 March 1939 · treaty
The UK and France guarantee Polish independence.
1 April 1939 · crisis · force
The Spanish Civil War ends in Nationalist victory; Franco becomes head of state.
7 April 1939 · crisis · force
Italy invades Albania (7–12 April) and later annexes it.
18 April 1939 · conference
The USSR's proposed tripartite alliance with the UK and France is rejected.
28 April 1939 · treaty
Hitler renounces the Anglo-German Naval Agreement.
29 April 1939 · treaty
Hitler renounces the German–Polish non-aggression declaration.
22 May 1939 · treaty
Italy and Germany sign the Pact of Steel, with a secret military alliance.
31 May 1939 · treaty
Denmark and Germany sign a non-aggression pact.
7 June 1939 · treaty
Germany concludes non-aggression pacts with Estonia and Latvia.
23 August 1939 · treaty
The Molotov–Ribbentrop Pact is signed, with secret provisions dividing Eastern Europe.
25 August 1939 · treaty
The Anglo-Polish alliance is signed; Hitler delays the invasion of Poland by five days.
31 August 1939 · crisis · force
The Gleiwitz incident, a staged attack, provides a pretext for war with Poland.
Sources
- Timeline of events preceding World War II · Wikipedia (EN)
- Interwar period · Wikipedia (EN)