King Ralph
In the film, the entire Wyndham family (based on the real-world House of Windsor), which in this film is the current ruling family of the United Kingdom, is wiped out in a freak accident. The family is together for the first time in six years when they are electrocuted after the metal platforms they are standing on for a family photograph become wet during a storm. There are no known members of the Wyndham family left alive.
The British government immediately begins a search led by courtier Cedric Willingham to learn whether there are any surviving heirs to whom to pass the crown. A researcher finally locates a living heir named Ralph Jones (John Goodman), an American.
In Las Vegas, Ralph works as a lounge singer/piano player in one of the main casinos. He is an easygoing slob, singing the Don Ho piece Tiny Bubbles while watching an American football game on TV. Duncan Phipps and Inspector McGuire (Niall O'Brien) watch the performance and applaud with enthusiasm. When Ralph returns to his room, he discovers that he's been fired for not performing to expected standards and replaced by a chimpanzee. Ralph meets Phipps and McGuire, who inform him that he is now king, though at first Ralph is skeptical over Phipps' claims. Phipps explains that Ralph's grandfather, the first Duke of Warren, had had a brief affair with a hotel maid while visiting the States, and this affair produced a child, Ralph's father. But since his father and grandmother have died, Ralph is the only surviving Wyndham heir. Ralph is finally convinced when seeing the Duke's ring, an exact copy of one the Duke had given to his grandmother.
Ralph is flown to London, where he meets Willingham for the first time and begins the long period of adjustment instruction intended to turn him into a proper British monarch. Ralph also learns the hard way that the British monarch does not just "smile and wave".
Shortly after his arrival, Ralph heads for a local strip club, meeting the exotic dancer Miranda Greene (Camille Coduri). When she is unable to perform in front of a group of men and leaves the stage in embarrassment, Ralph decides he wants to meet her: he admires the fact that she could not bring herself to take off her clothes in public. She's skeptical of his claim to be the King, but Ralph proposes that if he can prove he is the King, Miranda will go on at least one date with him. Ralph's appearance on a newscast proves to Miranda that his claim is legitimate.
Meanwhile, Lord Percival Graves (John Hurt), Prime Minister Sir Geoffrey Hale (James Villiers), and Willingham meet at 10 Downing Street to discuss Ralph's selection as King. Graves is opposed to the idea of an American on the throne, and he proposes to declare the Wyndham line at an end and to replace it with the House of Stuart. As Graves is a Stuart, he would be next in line for the throne. Hale states that Jones has royal blood and adds that unless Jones commits a grievous error the country will have to live with him.
Graves also learns about the meeting between Miranda and Ralph and decides to use her as a way to cause embarrassment to Ralph and provide the excuse that Parliament needs to remove him from the throne. Graves offers Miranda money to maneuver Ralph into a compromising position, and Miranda initially accepts. Ralph and Miranda continue their relationship, soon beginning to fall in love. Miranda returns the money to Graves, telling him she wants no part of his scheme, but she doesn't know that Graves already has pictures. In order to protect Ralph, Miranda decides to break off the relationship.
Despite Ralph's initial reluctance to accept British culture, and his general ineptness in formal affairs, he does manage to make a strong positive impression on King Mulambon of Zambezi (Rudolph Walker) during the latter's first official State visit. While unorthodox, their cultural exchange becomes less formal as Ralph invites Mulambon out for a pint of beer and a game of darts. Afterward, Mulombon invites Ralph to try the Zambezi version of darts—which involves hurling spears at a similar target—and the two share their concerns about both the role of leadership that they've assumed and the general economic interests of their respective nations. Having turned his blue-collar background into an advantage, Ralph begins accumulating a small but loyal and compassionate following.
The English arrange for Ralph to marry the Finnish Princess Anna (Joely Richardson); Ralph soon receives Princess Anna, her father King Gustav (Julian Glover), and mother Queen Katherine (Judy Parfitt) on an official state visit. However, Graves has photos of Miranda and Ralph kissing passed around at a royal ball given in honor of the Finnish royals. These, along with Ralph's wild rendition of "Good Golly Miss Molly" on a harpischord, ruin any chance of a marriage between Ralph and Princess Anna and causes a Finnish company to award a coveted contract to the Japanese. Having failed to realize that the role of King comes with formal expectations, and that he cannot rely entirely on his charm or blue-collar background, Ralph accepts a stern rebuke from Sir Cedric Willingham and endeavors to set things right.
The palace staff begins an investigation and soon realizes that Ralph was set up. It was Graves who arranged to have the pictures taken, and Miranda confesses to Ralph her role in the scandal. Ralph finally learns that there is another heir to the throne, and Willingham admits that he is this second heir and had initially refused to accept the role.
The next day Ralph addresses Parliament. Finally adopting the dignified manner and composure befitting a monarch, he publicly apologizes for his recent actions and then informs Parliament that he has helped work out a deal with the King of Zambezi that will create British jobs. Ralph then reveals that Graves has been working to sabotage his succession to the throne and has him arrested for violating the Treason Act of 1702. Finally, he tells the English people that while he tried his best to be a good king, he admits that his best will never be good enough and that he believes the English people deserve a better monarch. Thus, he has decided to abdicate his throne, and reveals that Willingham will take the throne.
Willingham becomes King Cedric I, and Ralph is free to pursue his romantic relationship with Miranda, along with his dreams of being a rock n' roll star. Ralph bids a tearful goodbye to his friends and his newly discovered relative, King Cedric. Cedric gives Ralph a lucrative annual salary, a home in the country, and a state-of-the-art recording studio. Later, Cedric names Ralph the 3rd Duke of Warren. In the end, a snapshot from the future is shown: Miranda is sitting with Ralph's young son, watching her husband perform with his musical group. The child is identified in the credits as Baby Ralph II, suggesting that he might someday succeed Cedric as monarch.
