Guy Pedroncini wrote the biography of this man, who ranks as France's oldest head of state?
Guy Pedroncini: Guy Pedroncini was a French academic and military historian specialising in the First World War, and notable as the biographer of Philippe Pétain and for his work on the French army mutinies of 1917. Philippe Pétain:  Pétain, who was 84 years old in 1940, ranks as France's oldest head of state.
i don't know