What was the role of Poland in World War 2?

Poland was invaded in September 1939 by Germany from the West and the Soviet Union from the East.

After the fall of Poland, many Polish soldiers escaped West to join the fight against the Germans. There were several Polish divisions which fought in the British army, and they achieved many notable victories, including the Battle of Monte Cassino. Many Polish Pilots joined the RAF, and a large number of German planes shot down during the Battle for Britain were shot down by Polish Pilots.

The Polish resistence movement also fought against the Germans, including the failed Warsaw uprising. Apart from fighting, the Polish also helped crack the enigma code.