Sir Eustace, with his little force, now reduced to half its number, was, as it happened, in front of the army when the ford was discovered, and, followed by his two esquires and ten mounted men-at-arms, dashed into the river, while the archers, slinging their bows behind them, drew their axes and followed. For a short time there was a desperate conflict, but as reinforcements hurried across, the fight became more even and the French speedily gave way. When the king had crossed he thanked Sir Eustace for his prompt action.

"Had you waited to send back for orders," he said, "the French would have come up in such numbers that the ford would not have been won without heavy loss, whereas by dashing across the moment it was discovered, you took the defenders by surprise and enabled us to get over without the loss of a single man."

The constable, disconcerted at finding that all his plans for keeping the English on the left bank of the river were foiled, fell back to St. Pol in Artois. Henry followed, but without haste. His small force was greatly reduced by sickness, while by this time the whole of the royal army had marched round and joined that of the constable. On the day after the passage had been effected three heralds arrived in the English camp to acquaint the king with the resolution of the constable and of the Dukes of Orleans and Brabant to give his army battle before he reached Calais. Henry replied that fear of them would not induce him to move out of his way or to change the order of his march; he intended to go on straight by the road to Calais, and if the French attempted to stop him it would be at their peril; he accordingly continued to advance at the same rate as before.