How many movies have Fritz Lang and Mia May collaborated on?

They have worked on 5 movies together! Their first movie together was Hilde Warren and Death (1917) while their highest rated movie together was The Mistress of the World, Part VIII: The Revenge of Maud Fergusson (1920). They have not worked together since The Indian Tomb, Part II: The Tiger of Eschnapur (1921). They are most known for their drama films together.