It is notoriously difficult to know the mind of a medieval hero. Henry V was the paradigm case of the hero-king. No other English notable of the Middle Ages comes close to matching his reputation, with the possible exceptions of Edward III and the Black Prince, and they outlived their triumphs to die in middle or old age, overshadowed by failure. Henry V was more fortunate. The victor of Agincourt and conqueror of half of France died in a French royal fortress at the age of just thirty-six, too soon to look failure in the face. He left an impossible legacy to his successors and their reverses only served to enhance his fame.

As a result, Henry became an icon: an idealised image of kingship, the outline blurred by incense, the voice drowned out by adulation and the personality hidden behind a crust of legend. We know much more about the inner lives of failures. Edward