Made in both German and English, this morality tale directed by Josef von Sternberg portrays the fall and humiliation of a Shakespeare teacher.
Prof. Immanuel Rath (Emil Jannings) is mocked by his students and finds photos of a local nightclub singer among them. Determined to save them from this influence, he attends the Blue Angel nightclub. In her dressing-room he is fascinated by Lola (Marlene Dietrich). A student sneaks her panties into the professor's coat pocket, and he goes back to return them the next night. Beginning to drink, he stands up for her and is soon seduced by her singing how she is "made for love from head to toe." Having spent the night with Lola, he is late to class and is reprimanded by his administrator for jeopardizing his respected pedagogical career for such a woman. The professor announces that she will be his wife.
Soon they are married, and the professor begins selling to customers her photos he disdained. His dignity gone in five years, he has been reduced to a pathetic clown, who assists a sleight-of-hand magician. His humiliation is complete when he must appear in the Blue Angel nightclub before his former colleagues and students while Lola is being romanced by a strong man. Barely able to make it through the act, the professor turned clown staggers back to his old school classroom where he is found clutching his desk.
This erotic parable symbolizes the plight of German intellectuals between two disastrous wars, as the humiliation of Germany from losing a world war going unresolved is soon to lead to the rise of the Nazi party and an even worse war. The educated mind can easily look down on sensual pleasures, partly from the fear such desires will make a fool of even the most intellectual man. This insecurity often accounts for the zeal with which some attempt to suppress such basic instincts. Yet the seed of the professor's humiliation is found in the students, who rebel against the respect for teachers demanded as they call him "garbage" and make fun of his infatuation. In this decadent German period the forces of degeneration are overcoming a professor named Immanuel perhaps after Christ or Kant.