The full 1920m trailer for The Golem: How He Came into the World (Der Golem)
The Cabinet of Dr. Caligari (Das Cabinet des Dr Caligari)
An article discussing German Expressionist Cinema
1920 in Film - a Wikipedia entry (there was a lot going on...just look at who was born in October 1920...)
The top image is from The Golem and the image below is from The Cabinet of Dr. Caligari.