The secrets of the Mona Lisa are unveiled – the brazen theft and how it became the most famous painting in history. The official portrait of Napoleon’s coronation is scrutinized to reveal a canvas of lies. We re-stage the freak jousting accident that killed a French king and find out whether modern medicine could have saved him. And we probe a king’s murder to discover if the assailant was a lone assassin or in league with a conniving queen.