In 1866 a nearly 300-pound bankrupt butcher with a thick Cockney accent stepped off a ship in London and claimed to be the long-lost aristocratic heir to the Tichborne fortune, a slender, French-speaking gentleman. Astonishingly, the grieving matriarch of the family looked at him and declared, that is my son.

This episode unravels one of the longest trials in British legal history, tracing how a mother's blinding grief and the public's class resentment turned an outlandish impostor into a working-class hero, and how the fraud finally collapsed.

• The real Roger Tichborne's disappearance at sea aboard the Bella in 1854
• Lady Tichborne's newspaper ads that effectively handed the claimant a script
• Evidence the claimant was really Arthur Orton, a butcher's son from Wapping
• Selling Tichborne bonds to the public to ...