The film begins with Flashman making a patriotic speech to the boys of Rugby School framed by a giant Union Flag, in a scene which appears to be a parody of the opening sequence in the 1970 filmPatton. There is a brief flashback to the events of the original Flashman, with the head of the Rugby School recounting Flashman's exploits in Afghanistan. The film then follows the plot of the book, which itself largely derives from The Prisoner of Zenda. Flashman is forced by Otto von Bismarck to impersonate a Danishprince, who is about to marry a German princess. Bismarck exacts this retribution partly in revenge for his humiliation at the hands of Flashman in London; Flashman stole Bismarck's mistress Lola Montez, then manoeuvred him into boxing against a professional boxer, John Gully, at a house party. Bismarck does not wish the Princess to marry a Dane, since this may tilt the balance on the Schleswig-Holstein Question and interfere with his plans for a united Germany.
Flashman, the first novel of The Flashman Papers series, had been published in 1968 and attracted the interest of film producers. At one stage Richard Lester was to direct, but the necessary financing could not be secured. However, Lester enjoyed the novel and then hired George MacDonald Fraser to adapt The Three Musketeers for two successful films in the early 1970s. This enabled Lester to obtain finance for a Flashman film. Royal Flash was the second Flashman novel, and had been published in 1970. The New York Times said "Mr MacDonald Fraser has considerable narrative skill... most ingeniously plotted and often hilariously funny." Diabolique argued the second novel was chosen for filming as opposed to the first because it would be less expensive, and the basic storyline had been successfully used before. The film was one of the first produced by executive David Picker following his resignation from being head of United Artists in 1973. In 1969 John Alderton had been cast as Flashman and he has a small role in Royal Flash. But the lead in was played by Malcolm McDowell. The film was shot partly on location in Bavaria. It introduced actors Bob Peck, and Christopher Cazenove. The film was cut from 118 minutes to 102 minutes prior to release. Among the scenes lost were flashbacks to Flashman's life at school, and the entire role of Roy Kinnear.
Reception
The Observer said the film "leaves one breathless not so much with enchantment as with boredom". The Wall Street Journal said it was "disappointing". Lester said the film was "generally ignored and considered to be a substandard version of The Three Musketeers. It was perhaps a poor choice of mine to pursue because it was a period film, a comic romp with some serious overtones and a lot of swordplay and it did come after Musketeers which was a well loved piece of subject matter." Lester also felt "that equivocal anti hero wasn't easy to take. They wanted a real hero, a hero that was a bounder as well as a hero. And Malcolm McDowell was absolutely 100% bounder - the sleaze was coming through to the film." Diabolique magazine argued the film suffered from miscasting in key roles, lack of voice over and for perhaps not being the best introduction to Harry Flashan for cinema audiences. Despite the film's disappointing reception, Lester said it was one of the few films he made that he liked watching again.