The river Somme now barred the passage of Edward. Most of the bridges had been destroyed, and those remaining were so strongly fortified that they could not be forced.

The position of the English was now very critical. On one flank and in front were impassable rivers. The whole country was in arms against them, and on their rear and flank pressed a hostile army fourfold their strength. The country was swampy and thinly populated, and flour and provisions were only obtained with great difficulty. Edward, on finding from the reports of his marshals who had been sent to examine the bridges, that no passage across the river could be found, turned and marched down the river toward the sea, halting for the night at Oisemont.

Here, a great number of peasantry attempted a defense, but were easily defeated and a number of prisoners taken. Late in the evening the Earl of Warwick, who had pushed forward as far as Abbeville and St. Valery, returned with the news that the passages at those places were as strongly guarded as elsewhere, but that he had learned from a peasant that a ford existed somewhere below Abbeville, although the man was himself ignorant of its position.

Edward at once called the prisoners belonging to that part of the country before him, and promised to any one who would tell him where the ford lay his freedom and that of twenty of his companions. A peasant called Gobin Agase stepped forward and offered to show the ford, where at low tide twelve men could cross abreast. It was, he said, called La Blanche Tache.

Edward left Oisemont at midnight and reached the ford at daylight. The river, however, was full and the army had to wait impatiently for low tide. When they arrived there no enemy was to be seen on the opposite bank, but before the water fell sufficiently for a passage to be attempted, Sir Godemar du Fay with twelve thousand men, sent by King Philip, who was aware of the existence of the ford, arrived on the opposite side.

The enterprise was a difficult one indeed, for the water, even at low tide, is deep. Godemar du Fay, however, threw away part of his advantage by advancing into the stream. The English archers lined the banks, and poured showers of arrows into the ranks of the enemy, while the Genoese bowmen on their side were able to give comparatively little assistance to the French.

King Edward shouted to his knights, "Let those who love me follow me," and spurred his horse into the water. Behind him followed his most valiant knights, and Walter, riding close to the Prince of Wales, was one of the foremost.

The French resisted valiantly and a desperate battle took place on the narrow ford, but the impetuosity of the English prevailed, and step by step they drove the French back to the other side of the river. The whole army poured after their leaders, and the French were soon entirely routed and fled, leaving two thousand men-at-arms dead on the field.

King Edward, having now freed himself from the difficulties which had encompassed him on the other side of the river, prepared to choose a ground to give battle to the whole French army.

Louis had advanced slowly, feeling confident that the English would be unable to cross the river, and that he should catch them hemmed in by it. His mortification and surprise on finding, when he approached La Blanche Tache, that twelve thousand men had been insufficient to hold a ford by which but twelve could cross abreast, and that his enemy had escaped from his grasp, were great. The tide had now risen again, and he was obliged to march on to Abbeville and cross the river there.