Adapted from Clyde Fitch’s play, the outspoken Brummel becomes a close friend of the Prince of Wales by giving him frank advice, and he attempts to influence the improvement of fashions while helping his royal friend.
In the era of Napoleon the Prince of Wales (Peter Ustinov) supervises a contest of horsemanship in which Captain George Bryan Brummel (Stewart Granger) excels, though he insults the prince with his comment on the uniforms.
At a banquet the prince conducts the orchestra. Lady Patricia Belham (Elizabeth Taylor) says that she will probably marry Lord Edwin Mercer (James Donald). Brummel asks to see the Prince and removes Patricia’s earrings because they embellish what is perfect. Brummel admits he is revolutionary, and the Prince dismisses him from his regiment. Later Patricia advises Brummel to apologize, but he does not agree and kisses her. Mortimer (James Hayter) asks Brummel if he can be his gentleman’s gentleman.
Brummel asks for a loan but is turned down. Brummel hears Ralph Sidley giving a political speech and questions him about the Prince, whom he criticizes. A reporter speaks to Brummel, who gives a speech himself.
The Prince tells William Pitt (Paul Rogers) he will not marry a German. The Prince is trying to lose weight. Pitt says people disapprove of him. Brummel comes in and verbally spars with the Prince. Brummel urges the Prince to tell others what to do rather than obey them. They talk in a steam bath. The Prince says the King hates him and may be out of his mind. The Prince decides not to go to Germany and goes to watch his horse win the race. Brummel meets Lord Byron (Noel Willman). Pitt warns Brummel about advising a prince. Brummel asks Patricia if he can call on her.
Brummel tries on his new suit he designed and tells Silva he will pay his account at the end of the year. Brummel gives the Prince a music box for his birthday and is the first to wear trousers. Edwin lets Patricia dance with Brummel, who says Pitt and Edwin are against him. Brummel gives her his address. The Prince is in love with Maria Anne Fitzherbert (Rosemary Harris) and wants to marry her. The Prince offers to make Brummel a major, but he prefers to be a friend of the Prince. Mortimer tells Brummel that Silva is asking for money. Patricia calls on Brummel, and he shows her his elegant house. Brummel says the Prince will be a good king. In his study he asks her to stay with him. She feels he is heading for disaster, but she kisses him before running out. Brummel tells Mortimer that he will marry her.
In a carriage Edwin tells the Prince and Brummel that he is going to marry Patricia. Brummel gets out of the carriage and takes two dogs from a man who is whipping them and gives one to the Prince. The Prince takes Brummel to his club and makes him a member. Lord Mindon objects to Brummel and says his grandfather was a valet. Pitt tells Brummel he will help him stand for Parliament. Brummel suggests a new government.
Brummel designs a red hunting coat to be easily seen. The Prince proposes a toast to Brummel and promises him an earldom. Patricia announces her marriage to Edwin. Maria tells the Prince she is thinking of going to Italy. Edwin realizes that Patricia wants Brummel, but she says he is bad for her. They go on a fox hunt, but Brummel follows Patricia. She slaps him, but he makes her kiss him. Edwin asks her to wait a decent interval before jilting him. She tells Edwin she will never see Brummel again.
The Prince calls on Brummel and says Maria is going. Brummel says he is in the same position. Brummel tells him to certify the King as insane so that Parliament will make him regent. They go to see George III (Robert Morley), who hides and tells a servant not to trust princes. George III sits on his throne and prays to God to remove his sickness. The Prince tells Brummel he will not go in, but Brummel goes in with the doctors. George III says he is well. Brummel has the Prince come in, but George III denies he is his son and tries to choke him.
The Prince plays the harp and talks to Brummel while they wait for word from Parliament about his regency. Pitt, Fox, and Burke come in and say that the regent will not be able to grant peerages. Brummel says it is a question of who rules. Pitt recessed the Parliament and says the King may recover. They leave, and the Prince tells Brummel he wants to marry Maria. The Prince blames Brummel because he wants to be an earl. He ends the friendship, and Brummel withdraws.
Byron calls on Brummel and says the commission is reporting that the King has recovered. Byron says the Prince regrets their quarrel. The Prince enters a ball with Maria, and only Brummel does not bow. Brummel speaks to Maria, and the Prince talks to Byron. Brummel refers to the Prince as fat.
Patricia calls on Brummel, embraces him, and says she will never leave him again. He says he may be in debtors prison, and so he must go away. She says she will wait, and they kiss. Brummel tells Mortimer to pack.
George III dies, and the Prince becomes George IV. Edwin calls on him, and George IV says he may visit the continent. He wants to help desperate Brummel discreetly. McIver tells Brummel that his book will be a success; but Brummel says he will not publish it because he does not want to hurt George or Maria. McIver says he gave him an advance and insists on publishing it; but Brummel throws the manuscript in the fire. Mortimer asks if he should get a doctor. Brummel says he will not see the visiting King.
Brummel watches George IV arrive at Calais. George tells Patricia and Edwin that Brummel has denied all help. A Frenchman calls George a pig. Brummel objects and is thrown in the mud. George calls on the ill Brummel, and a doctor says he is dying. Brummel thanks the King for coming. Brummel asks about Byron, Pitt, Patricia, and Edwin. Brummel says they never stopped being friends. They say goodbye. George tells the others it is not how a man ends up but how he has affected others. Brummel tells Mortimer that he must sleep.
This biographical drama depicts a friendship between a self-confident man and a prince who needs an honest advisor. Beau Brummel is known for being a dandy and an innovator in dress. He had pride in his appearance and difficulty in compromising or in working to achieve success that would pay the bills. The woman he loved realized that he was headed for disaster. Yet the positive influence he had on a king was known to that king.