17 September 1939 at dawn on the territory of Polish, struggling with German aggression, about 50 divisions of the Red Army invaded. The Soviet invasion, which in England was called a "backstab", resulted from the the desire to occupy the eastern territories of the Second Republic of Poland, in accordance with the division of spheres of influence in the secret protocol to the Molotov-Ribbentrop Pact. Soviet aggression was violation of the Treaty of Riga of 1921, the Polish-Soviet Treaty on the non-aggression of 1934, as well as international agreements signed by Poland and USSR. The entry of Soviet troops finally paralyzed the resistance of the troops and caused the departure of the Polish authorities to Romania.