Man of La Mancha (1972)

This musical version of Don Quixote is framed by an incident allegedly from the life of its author, Miguel de Cervantes. Don Quixote is the mad, aging nobleman who embarrasses his respectable family by his adventures. Backed by his faithful sidekick Sancho Panza, he duels windmills and defends his perfect lady Dulcinea (who is actually a downtrodden whore named Aldonza).