German Expressionism developed in Germany during the Weimar period of 1919-1933 following World War 1. Artists responded to the social conditions including the aftermath of war, with men returning physically and psychologically damaged, and economic hardships including hyperinflation. Expressionist art portrayed inner psychic states rather than outer appearances, using distorted forms and colors to represent emotions. Major Expressionist groups included Die Brucke and Blaue Reiter, and the style influenced influential German films of the era seeking to depict internal experiences, such as The Cabinet of Dr. Caligari and Nosferatu.