Hundred Years' War English-occupied Calais. In a campaign reminiscent of Crécy, he found himself outmanoeuvred and low on supplies and had to fight a much larger French army at the Battle of Agincourt, north of the Somme. Despite the problems and having a smaller force, his victory was near-total; the French defeat was catastrophic, costing the lives of many of the Armagnac leaders. About 40% of the French nobility was killed. Henry was apparently concerned that the large number of prisoners taken were a security risk (there were more French prisoners than there were soldiers in the entire English army) and he ordered
English longbow best-equipped) nobles, remained comparatively unhurt by the English arrows". Archery was described by contemporaries as ineffective against plate armour in the Battle of Neville's Cross (1346), the siege of Bergerac (1345), and the Battle of Poitiers (1356); such armour became available to European knights and men at arms of fairly modest means by the late 14th century, though never to all soldiers in any army. Longbowmen were however effective at Poitiers, and this success stimulated changes in armour manufacture partly intended to make armoured men less vulnerable to archery. Nevertheless, at the battle of Agincourt in 1415 and for some