In an accidental but illuminating coincidence, two powerful new productions turn on trials involving famous historical figures. Jonathan Lynn – most associated with a political comedy that was a TV and theatre hit, the Yes, Minister franchise that he created with Antony Jay – has dramatised a political tragedy in his first solo stage play, The Patriotic Traitor. Tom Conti, adopting an accent that wanders  across northern parts of the UK, is Philippe Pétain, the French First World War hero who became a mentor of a young soldier, Charles de Gaulle, whom Laurence Fox invests with an absolute severity and certainty that previews the general’s later political reputation.De Gaulle, an intellectual with a passion for poetry and philosophy, and Marshall Pétain