siege of Aiguillon in the south-west. After his surprise landing in Normandy, Edward was devastating some of the richest lands in France and flaunting his ability to march at will through France. On 2 August, a small English force supported by a large number of Flemings invaded France from Flanders. French defences were completely inadequate. On 29 July, Philip proclaimed the arrière-ban for northern France, ordering every able-bodied male to assemble at Rouen, where Philip himself arrived on the 31st. He immediately moved west against Edward with an ill-organised and poorly-equipped army. Five days later he returned to Rouen and broke the bridge over the Seine behind him. On 7 August, the English reached the Seine, south of Rouen, and raided up to its suburbs. Philip, under pressure from representatives of the Pope, sent envoys offering peace backed by a marriage alliance; Edward replied that he was not prepared to lose marching time to futile discussion and dismissed them. By 12 August, Edward's army was encamped at Poissy, 20 miles from Paris, having left a swath of destruction down the left bank of the Seine to within of the city. On 16 August, Edward burnt down Poissy and marched north. The French had carried out a scorched earth policy, carrying away all stores of food and so forcing the English to spread out over a wide area to forage, which greatly slowed them. Bands of French peasants attacked some of the smaller groups of foragers. Philip reached the River Somme a day's march ahead of Edward. He based himself at Amiens and sent large detachments to hold every bridge and ford across the Seine between Amiens and the sea. The English were now trapped in an area which had been stripped of food. The French moved out of Amiens and advanced westwards, towards the English. They were now willing to give battle, knowing that they would have the advantage of being able to stand on the defensive while the English were forced to try and fight their way past them. Edward was determined to break the French blockade of the Somme and probed at several points, vainly attacking Hangest and Pont-Remy before moving west along the river. English supplies were running out and the army was ragged, starving and beginning to suffer from a drop in morale. On the evening of 24 August, the English were encamped north of Acheux