The invasion of Poland marked the start of World War II in Europe, as Poland's western allies, the United Kingdom, Australia and New Zealand, declared war on Germany on September 3, soon followed by France, South Africa and Canada, among others. The invasion began on 1 September 1939, one week after the signing of the Molotov–Ribbentrop Pact, and ended 6 October 1939, with Germany and the Soviet Union occupying all Poland. Although the United Kingdom and France declared war on Germany soon after Germany attacked Poland, very little direct military aid was provided.

Following a German-staged "Polish attack" on 31 August 1939, on 1 September German forces invaded Poland from the north, south, and west. Spread thin defending their long borders, the Polish armies were soon forced to withdraw eastward. After the mid-September Polish defeat in the Battle of the Bzura, the Germans gained an undisputed advantage. Polish forces then began a withdrawal southeast, in accordance with a plan that called for a long defense in the Romanian bridgehead area. Here they were to await an expected Allied counterattack and relief.

On 17 September 1939, the Soviet Red Army invaded the eastern regions of Poland in cooperation with Germany. The Soviets were carrying out their part of a secret appendix to the Molotov-Ribbentrop Pact, which divided Eastern Europe into Nazi and Soviet spheres of influence. Facing a second front, the Polish government decided the defense of the Romanian bridgehead was no longer feasible and ordered an emergency evacuation of all troops to neutral Romania. By 1 October, Germany and the Soviet Union had completely overrun Poland, though the Polish government never formally surrendered territorial control. In addition, Poland's remaining land and air forces were evacuated to neighboring Romania and Hungary. Many of the exiles subsequently joined the recreated Polish Army in allied France, French-mandated Syria, and the United Kingdom.

Following nearly six years of Nazi occupation, Poland fell under the control of the Soviet Union which established a satellite regime and a Communist dictatorship. It was brought down in 1990 by the popular swell of the Solidarity labor movement. Today Poland is an independent nation ruled by democratic process. Its territory has changed, shifted westward by the acquisition of former German province and the loss of its eastern provinces to Russia, Belorussia and the Ukraine.

Among the nations caught up in World War Two, Poland shares with the former Soviet Union the greatest losses among its soldiers and civilians. Poland was also the site of many Nazi extermination camps, including Auschwitz and Treblinka.

I salute the nation of Poland and its people for being the first to fight against the monstrous Nazi war machine.

"Wygrana Polska!"