How many movies have Erna Morena and Richard Oswald collaborated on?

They have worked on 4 movies together! Their first movie together was Diary of a Lost Woman (1918) while their highest rated movie together was Die Liebschaften des Hektor Dalmore (1921). They have not worked together since Die Liebschaften des Hektor Dalmore (1921). They are most known for their drama films together.