The film opens with a passage, which states:
This film is based on a recently discovered manuscript by one William Cobbler, which reveals that Henry VIII did in fact have two more wives. Although it was first thought that Cromwell originated the story, it is now known to be definitely all Cobbler's... from beginning to end.
Henry VIII (Sid James) has his wife (Patsy Rowlands) beheaded and quickly marries Marie of Normandy (Joan Sims). This union was organised at the behest of bumbling Cardinal Wolsey (Terry Scott) as Marie is cousin of King Francis I of France. Before the marriage can be consummated, Marie eats a clove of garlic, claiming it is a Normandy tradition. Henry is repulsed by the smell and leaves. Marie receives amorous advances from Henry's attaché Sir Roger de Lodgerley (Charles Hawtrey who, while still in his camp persona, is playing against type as a ladies' man).
Henry is keen to be rid of Marie, and seizes the opportunity to divorce her when he discovers she is pregnant with Lodgerley's child. He imprisons her in the Tower of London and commands Thomas Cromwell (Kenneth Williams) to retrieve a confession of paternity from Lodgerley. Marie convinces Wolsey to send for the French ambassador, who tells Henry that Francis, King of France (Peter Gilmore) is so thrilled with the match that he will give England ten thousand gold pieces. This, and the fear that the ambassador will discover Marie's imprisonment, convinces Henry to release Marie; he commands Cromwell to force a retraction of Lodgerley's confession.
Soon afterwards, Henry meets the beautiful Bettina (Barbara Windsor, in her favourite Carry On role). Bettina is the daughter of the Earl of Bristol (Peter Butterworth, in a one scene cameo), a punning reference to Bristols. Henry renews his attempt to divorce Marie just as Lodgerley signs his retraction, again imprisoning Marie in the Tower. Henry comes so close to achieving the divorce that he sends Bettina to the bridal bedchamber. The handsome King of France arrives on a surprise visit and finds Bettina; finding her to be a suitable wife, he asks Henry if he can marry her. Henry realises that the only way to avoid war with France is to consent. Henry arranges for Cromwell and Wolsey to be executed as a result of their supposed inaction. Charmed by Henry's loyalty, Marie announces that she loves him and goes into labour. Henry promises to be a faithful husband, but immediately meets Catherine Howard. He rushes to stop the execution of Cromwell and Wolsey, begging for their help in divorcing Marie and ensuring marriage with Howard, but both men cry out 'carry on, executioner!'.
Sid James as King Henry VIII
Kenneth Williams as Thomas Cromwell
Charles Hawtrey as Sir Roger de Lodgerley
Joan Sims as Queen Marie of Normandy
Terry Scott as Cardinal Wolsey
Barbara Windsor as Bettina
Kenneth Connor as Lord Hampton of Wick
Julian Holloway as Sir Thomas
Peter Gilmore as Francis, King of France
Peter Butterworth as Charles, Earl of Bristol
Julian Orchard as Duc de Poncenay
Gertan Klauber as Bidet
David Davenport as Major-domo
Margaret Nolan as Buxom lass
William Mervyn as Physician
Norman Chappell as 1st plotter
Derek Francis as Farmer
Bill Maynard as Fawkes
Douglas Ridley as 2nd plotter
Leon Greene as Torturer
David Prowse as Torturer
Monica Dietrich as Catherine Howard
Billy Cornelius as Guard
Marjie Lawrence as Serving maid
Patsy Rowlands as Queen
Alan Curtis as Conte di Pisa
John Bluthal as Royal tailor (uncredited)
Bill McGuirk as Flunkey (uncredited)
Jane Cardew as Henry's 2nd wife (uncredited)
Valerie Shute as Maid (uncredited)
Peter Rigby as Henry's courtier (uncredited)
Trevor Roberts as Henry's courtier (uncredited)
Peter Munt as Henry's courtier (uncredited)
the 21st release in the series of 31 Carry On films (1958–1992).