The Dark Avenger was the European-release title of the Errol Flynn swashbuckler The Warriors; 20th Century-Fox handled European distribution, while Allied Artists released the film stateside. Lensed on location in Hertfordshire, England, the film stars Flynn as Edward, the "Black Prince" of England. At the end of the Hundred Years' war, Edward remains in France to guard the lands taken by his predecessor-father. He is opposed in this by the heavy of the piece, Count DeVille (Peter Finch). The story comes to a rousing conclusion as Edward and his followers defend their castle against DeVille's minions. Joanne Dru costars in Dark Avenger as Lady Joan Holland, who like Count DeVille is wholly a product of screenwriter Daniel B. Ullman's imagination.
~ Hal Erickson, All Movie Guide