Young and idealistic, the Prince of Wales develops a deep affection for a beautiful quakeress, Hannah Lightfoot, who catches his eye as he is riding through the streets. A first meeting is arranged, leading to several more, and eventually they discreetly marry in a secluded house where they live as man and wife. She is prepared to betray her beliefs for him, just as he is willing to defy the desires of various courtiers for her. Eventually, his mother's lover Lord Bute uncovers the affair and Hannah mysteriously disappears.
The novel explores the lasting question, did the future George III contradict royal protocol and marry a commoner? Shortly after his affair with Hannah, he becomes King George III. After a potential engagement to Sarah Lennox falls through, he marries Princess Charlotte of Mecklenburg-Strelitz.