But Henry was not yet satisfied. Two-thirds of his force had melted away, dead or invalided, but he had no intention of re-embarking at Harfleur. He devoted a fortnight to the repair of the defences of the captured town, and then collecting provisions for eight days he marched northward for Calais with an army, or, as we should now call it, a flying column, of nine thousand men.
Meanwhile the French, disorganised though they were by the insanity of their king, Charles the Sixth, began to bestir themselves, and collecting an army of sixty thousand men, fourteen thousand of them men-at-arms and several thousand archers and cross-bowmen, determined to hold the line of the Somme and bar Henry's passage of the river. Henry's idea, dictated like the whole of his campaign by the precedent of Edward the Third, had been to cross the Somme by the ford of Blanche Tache. He now learned that the passage was defended by the French in force. He wheeled at once to the right, and following the left bank of the river upward, tried in vain to find a crossing-place. Every bridge was broken down and every ford beset. It was plain that he was more effectually entrapped even than his predecessor Edward.
The eight days' supply of provisions was now consumed, and the position of the English became most critical. Retreat Henry would not, force the passage of the Somme he could not. He decided to follow the river upward to its head-waters, and on reaching Nesle learned from a countryman of a ford, the access to which lay across a morass. Two causeways that provided a footing over it had been broken down by the French, but these were quickly repaired with wood and faggots and straw till they were broad enough to admit three horsemen abreast. Henry himself was indefatigable in the work. He took personal charge of one end of the passages, and appointed special officers to attend to the other. The baggage was carried over along one causeway, and the men by the second. Thus the passage both of morass and river was accomplished between eight in the morning and an hour before dusk of an October day. The French, who were lying in force at Peronne, now for some unexplained reason retreated towards the north-west, but sent, according to custom, a challenge to Henry to fix time and place for battle. "I am marching straight to Calais through open country," he replied. "You will have no difficulty in finding me." And he continued his advance.