Who conquered Poland?

first answer: nazis

second more correct answer:

Nazi Germany began the invasion of Poland on 1 Sept. 1939, however the Soviet Union joined Germany in the invasion on 17 Sept. 1939. A conquered Poland was divided between the two invaders.

Then at the end of the war, when Germany was defeated, Poland (an ally) was not freed by the Soviets, instead it was occupied & turned into a puppet of the Soviets.