THE WAYS OF SIEGE WARFARE
Whatever troops or tactics were used, rulers and commanders were competing for the same territories and strongpoints. The sieges of Calais in the 1340s are one example. It looked like Edward III, following a dramatic victory over the French king at Crécy, might establish his regime in northern France. At the least, Edward wanted to gain control of some part of the coast, which would allow him easy access to France. Edward had enough troops and enough supplies to maintain a siege of Calais, a small but convenient French port. After a year-long attack, the starving defenders of Calais had to surrender in 1347.
The French were unhappy about this loss, and recovering Calais became a French priority. King Philip VI appointed Sir Geoffroi de Charny, one of the most respected French knights, to oppose the English. He energetically campaigned along the military frontier but was unable to make a dent in the English position, or to provoke them to fight a set-piece battle. Charny then tried a different tactic and planned a secret night attack that depended on treason. He located an Italian mercenary in the English garrison of Calais, Aimeric of Pavia, who agreed to allow the French into the fortification in exchange for 20,000 ecus.
A week before the attack, however, the English detected Aimeric’s treason. Aimeric convinced the English not to punish him; instead he was made the key figure in a new plan in
