Tony Robinson goes in search of the truth about one of Britain's most maligned monarchs, Richard III. Robinson investigates whether Richard really did murder his two nephews, the Princes in the Tower, aged nine and 12, before usurping the throne. And if he did, what were his real motives? But before the investigations comes to a close, an astonishing fact emerges that leads one to question the entire legitimacy of the last 500 years of British royalty.