Eighty years ago, German aggression on Poland started the Second World War. In the early hours of 1 September 1939, troops of the German Reich crossed the Polish-German border. Polish Army put up military resistance and expected the Allies’ reaction. On 3 September 1939, France and the UK declared war on the German Reich but did not take any real military action. Poland’s tragic fate was sealed on 17 September 1939 when the Soviet Union launched the invasion of Poland from the East. The attack of the German Reich and the Soviet Union resulted from the Molotov-Ribbentrop Pact signed by the two totalitarian regimes, a secret protocol to which effectively divided Central Europe into the so-called spheres of influence.