Iron Sky

"As World War II comes to an end in 1945, Hans Kammler and other German scientists make a breakthrough in anti-gravity research. From a secret base in the Antarctic, Nazi spaceships are sent to the "dark side" of the Moon to establish the military base "Schwarze Sonne" (Black Sun). Their plan is to build a powerful fleet and return to conquer Earth. The film is set in the year 2018 when their descendants finally return." Wikipedia says it better than I ever could.