Agincourt, by Juliet Barker

Why shots still fly around the band of brothers

Henry's huge invasion force was intended to take Harfleur, and progress either to Aquitaine or Paris. But Harfleur took more time and men to conquer than bargained for, and a much-depleted army marched for the English territory of Calais - and eternal fame. Historians are disunited over the battle's causes, course and outcome. The archers were less effective than once thought; the French nobly chivalric, rather than incompetent. Most controversial is the conclusion of the leading authority, Anne Curry, that the English were only outnumbered by four to three, not four or five to one.

In face of this regiment of experts, Barker's bravely opinionated book, substantial as it is, has something of David's slingshot - especially as she disagrees with Curry's assessment. Her most distinctive contribution is a perspective on medieval military thinking coloured by her impressive pedigree as an expert on tournaments and chivalry. This is a serious rather than sprightly book, but it is a milestone in Agincourt studies.