Complex sentence: Poelzig also worked as set designer and architect for film and theatre of the 1920s, the most important film in collaboration with him was' (1920) by Paul Wegener and Carl Boese.
Split into simpler sentences: Poelzig also worked as set designer and architect for film and theatre of the 1920s. The most important film in collaboration with him was' (1920) by Paul Wegener and Carl Boese.