Adventures of Don Juan (1948)

Don Juan de Maraña (Errol Flynn) is a Spanish nobleman with a reputation for having many lovers, but the woman who has truly captured his heart is none other than Queen Margaret (Viveca Lindfors), who is unhappily married to King Philip III (Romney Brent). When Don Juan uncovers a plot by the devious Duke de Lorca (Robert Douglas) to dethrone the royal family, he rallies his trusted friends and rushes to defend both his country and his beloved queen.