The Three Stooges S15E03 - Squareheads of the Round Table

Set in Arthurian times, the stooges decide to help their friend Cedric the Blacksmith win the hand of the fair princess Elaine. At night the group sneaks into the castle to serenade Elaine, but pick the wrong window and are caught by the King. Tossed in the dungeon, the boys escape with Cedric's help and manage to foil the plans of the Black Prince who was plotting against the King. All turns out well when the grateful King allows Cedric to marry Elaine.