What Started World War 2: Timeline

The cause of World War Two is often attributed solely to the invasion of Poland by Germany, which resulted in the deceleration of war by France and Britain. In this timeline the events leading up to this invasion are explored between the dates of 1933 and 1939 in order to better understand the motivations behind it...

World War II Causes: Important Events Between 1933-39

The question of whom or what started world war two cannot be pin pointed to a signal individual, or specific event. Please see below for a timeline of pre WW2 events that likely contributed to the eventual beginning of World War 2. For a more detailed narrative exploring the most likely causes a little deeper then please read What started World War Two post.



  • January 30: President Hindenburg appoints Hitler as chancellor.
  • January to February: Japan conquer the Jehol province in Chinese Manchuria.
  • February 24-25: League of Nations condemns Japan and calls for an end to the Japanese occupation of Manchuria. The Japanese delegation subsequently walk out.
  • March 5: Nazis secure 44% of the vote in Germany’s election.
  • March 23: Enabling Act is passed, which gives dictatorial powers to Hitler.
  • March 27: Japan announces its intention to leave the League of Nations.
  • May 31: Tangku Truce essentially eliminates China’s military presence in northern China and Inner Mongolia.
  • October 14: Germany leaves the League of Nations.


  • October 1: Hitler expands his army and navy, while also ordering the creation of an air force.
  • December 19: Japan refuses to be limited by future naval treaties.
  • December 30: Mussolini begins preparations for an Autumn invasion of Abyssinia.



  • March 7: Saarland restored to Germany.
  • May 2: The Soviet Union and France sign the Mutual Assistance Pact.
  • June 26: The British suggest a compromise to Mussolini over Abyssinia. The Italian rejects it.
  • September 15: Nuremberg Laws passed, which deprived Jews of German citizenship.
  • September 18: The Soviet Union joins the League of Nations.
  • October 3: Italy invades Abyssinia.



  • January 15: Japan withdraws from the Second London Naval Conference after their request for naval parity with Britain and the USA is refused.
  • February 26-29: Japanese army prevents an attempted coup to reform a civilian government.
  • March 7: Germany reoccupies Rhineland.
  • March 23: Italy, Austria and Hungary sign the Rome Pact.
  • May 9: Italy annexes Abyssinia.
  • July 18: The Spanish Civil War begins, between the republicans and Franco’s nationalists.
  • October 14: Belgium ends its military alliance with France.
  • November 1: Hitler and Mussolini sign the Berlin-Rome Axis.
  • November 18: Germany and Italy officially recognise Franco’s regime in Spain.
  • November 25: Germany signs the Anti-Comintern Pact with Japan.



  • February 8: In the south of Spain, Franco’s forces take Malaga.
  • April 26: The Axis powers bomb the Basque town of Guernica in Spain.
  • July 7: The Marco Polo Bridge incident outside Peking triggers Japan’s ‘undeclared war’ throughout China.
  • November 25: Italy joins the German-Japanese Anti-Comintern Pact.
  • December 13: Japanese occupy Nanking, committing widespread atrocities on the civilian population in the process.



  • March 12: German troops march into Austria, before annexing Hitler’s homeland.
  • April 23: Sudeten Germans in Czechoslovakia demand full autonomy.
  • April (unspecified): Japan’s National Mobilisation Law is passed, resulting in full military mobilisation.
  • September 29: Britain, France and Italy sign the Munich Pact which agreed to transfer Sudetenland to Germany.
  • October 21: Japanese capture Canton.
  • October (unspecified): The Chinese Nationalist government withdraws to Chungking.



  • January 27: Britain and France recognise Franco’s government.
  • March 15: Germany begins its occupation of the rest of Czechoslovakia.
  • March 21: Hitler demands that Poland returns Danzig to Germany.
  • March 23: Germany and the Soviet Union sign the Nazi-Soviet Pact, agreeing to the division of Poland. On the same day, Germany begins its occupation of Memel in Lithuania.
  • April 7: Italy invades Albania.
  • May 22: Germany and Italy agree a military alliance under the Pact of Steel.
  • May (unspecified): Japan launches long-range bombing raids on Chungking. Japanese troops also clash with their Soviet counterparts in the Nomonhan region.
  • August 23: Germany and the Soviet Union sign the Non-Aggression Pact.
  • August 25: Britain signs the Mutual Assistance Pact with Poland.
  • August-September: Japan beaten comfortably at Nomonhan, resulting in theSoviet-Japanese armistice on 16 September.
  • September 1: Germany invades Poland.
  • September 3: Britain and France declare war on Germany.

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Discover the major events between 1933 and 1939 that lead to Germany invading Poland and the subsequent outbreak of World War Two (WW2 or WWII).