While his army was crossing the river, Edward received the challenge of the King of France. It was native indeed to the time: a sort of tournament-challenge, offering the English monarch battle upon any one of five days, in that great plain between Paris and St Germains which the last siege of the French capital has rendered famous in military history. The French feudal levies for which Philip had been waiting were now fast gathering, especially those for which he had had to wait longest, the main forces which had been away down south in Guienne. Edward most wisely refused the challenge, for it would have been against great odds, and to accept, though consonant to the spirit of the time, would have been a ludicrously unmilitary proceeding. In place of such acceptation he sent back false news that he would meet Philip far to the south. He then proceeded to cross the river and make the best haste he could back northwards to the sea. The French King found out the trick; a day and a half late he started in pursuit with his large and increasing host. That host was gathered at St Denis when on the Wednesday night, the 16th, Edward had got his men to Grisy, well north of Pontoise, and something like seventeen miles by cross roads from his hastily repaired bridge across the Seine. What followed was a fine feat of marching. On the next day, the 17th, he had got his forces more than another seventeen miles north and had camped them by Auneuil. In two more days, by the evening of Saturday the 19th, they were yet twenty-five miles further north as the crow flies (and more like thirty by the roads), at Sommereux. Edward halted at Troussures (of which the clerk makes "Trusserux") to see it file by, and on the morrow, Sunday, August the 20th, he was at Camps in the upland above Moliens Vidame, another push of fifteen miles for mass of the force, and of more than twenty for himself and his staff. At this point came the crux of his danger. All during that tremendous feat of marching (and what it meant anyone who has covered close on fifty miles in three days under military conditions will know--there are few such) the great host of Philip was pounding at his heels. Now, if the reader will glance at the map at the beginning of this section, he will see that just as Edward had been under a necessity to cross the Seine in the first part of his raid, he was now under a still greater necessity of crossing the Somme. A force much larger than his own was pressing him against that river into a sort of corner, and his only chance of safety lay in reaching the Straits of Dover through the county of Ponthieu, which lay beyond the stream. Every effort had been made to press the march. The force appears to have been divided for this purpose and to have marched in parallel columns, and the single case of marauding (the burning of the Abbey of St Lucien outside Beauvais) had been punished with the death of twenty men.