1 September: Germany begins the Second World War with its invasion of Poland

Shortly after signing the German-Soviet Non-aggression Pact, including a secret protocol in which Hitler and Stalin agree on the division of Poland, Germany attacks its neighbour. The military campaign is completed in just five weeks. The Polish troops are poorly equipped and clearly outnumbered. As a result, France and England enter the war. In mid-September, Soviet troops march into Eastern Poland and occupy the regions negotiated in the secret protocol.