The situation upon Wednesday the 23rd of August (at which point we concluded the survey of Edward III.'s great raid through Normandy, and of his retreat down the line of the Somme) is already known to the reader, and will be the clearer if he will look at the map upon page 28. Edward had made a very fine march indeed, not only averaging something like twelve miles a day, or more, but arranging for expeditions to leave the main host during the latter part of this rapid retreat, and attempt to force, at various points, the passages of the River Somme. We have seen that he was compelled, if possible, to force a passage because he would otherwise find himself shut up between the Somme and the sea, with a much superior force cutting him off to the south. In case of defeat he would have no line of retreat, and even in case of success, unless that success were overwhelming, he would find himself strategically stalemated, still caught in a trap, and still doomed to await the next onslaught of the enemy. We have further seen that with every mile that he proceeded towards the sea his ability to cross the Somme decreased. The river runs through a marshy valley which, even to-day, is a mass of ponds and water meadows, and which then was a belt of marsh. It is bounded on either side by fairly steep banks, rising to heights of 60, 70, and 100 feet, and inland to 150, between which the flat swamped land grows broader and broader as one approaches the sea. At Picquigny this level belt of swamp through which the Somme twines is quite 500 yards across. At Long Pré it is nearer 800, below Abbeville it is 1000, and at the point whence Edward overlooked it when he was halted at bay on the evening of that 23rd of August, it is well over 2000 yards in width and nearer 2500. Boismont, a village climbing the southern bank of the estuary, was the spot on which the King had gathered the army upon the evening of that Wednesday, and, not a day's march behind him, the most advanced mounted men of his pursuers, with the King of France among them, were camping. The peril was extreme, and an issue from that peril as extremely doubtful. It was hopeless for the army to attempt to retrace its steps to the upper river. To have done so would have been to march with the flank of its march exposed to an immediate advance of French forces, and almost certainly to be caught in column; and Edward had already suffered such repulses before Long Pré, Pont Rémy, and Picquigny as left him no hope for success should he attempt these bridges again. His only chance was to find, if it were possible, some practicable ford across the broad estuary itself that lay before him.