When Operation Barbarossa began, the soviets released polish POW’s to fight nazi germanyand its axis allies. But the Germans were too fast for them. And so the Soviets let the poles to the middle east where they fought with the british. Later when the Soviets were winning, the polish people's army was formed and would later include the 1st army (1st, 2nd, 3rd, 4th, and 6th divisions) and 2nd army (1st corps and 5th, 7th, 8th, 9th, and 10th divisions).
Polish forces reached the occupied ares in July-august of 1944, liberating Warsaw in January of 1945 and liberating other areas.[1]
The 1st army fought Battle of Berlin and the 2nd army fought in the Prague offensive.[2][3]
In may of 1945, the Germans surrendered, ending the war.