On 1 September 1939, Poland was attacked by fascist Germany. UK and France declared war on Germany, but did little to help them, which is why it is called Phoney War (no battles took place). Poland was overrun by German forces and their capital - Warsaw fell on 28 September. Earlier, on 17 September, Soviet forces crossed Polish border, without declaration of war and annexed largely Belarussian and Ukrainian eastern part of Poland.