For all these causes Maubeuge, in common with other points along the Belgian frontier less important than itself, was left imperfect. Even if the ring fortress had remained after 1905 what it had been before that date, and even if modern howitzer fire and modern high explosives had not rendered its tenure one of days rather than months, Maubeuge was not a first-class fortress. As it was, with fortifications unrenewed, and with the ring fortress in any case doomed, Maubeuge was a death-trap. The rôle assigned to the fortress in the original French plan was no more than the support of the retiring operative corner, as it "retreated, manoeuvred, and held the enemy." Maubeuge was considered as part of a line beyond which the operative corner would not have to fall before the rest of the square, the "manoeuvring mass," had swung up. Hence it was that the French General Staff and its Chief had put within the ring of its insufficient forts nothing more than a garrison of Territorials--that is, of the older classes of the reserve. Had the British General accepted the lure of Maubeuge as Bazaine did the lure of Metz in 1870, the Expeditionary Force would have been destroyed. But it would have been destroyed, not after a long delay, as was the army at Metz, but immediately; for Maubeuge was not Metz, and the fortress power of resistance of to-day is not that of a generation ago. Maubeuge, as a fact, fell within a fortnight of the date when this temptation was offered to the sorely pressed British army, and had that temptation been yielded to, the whole force would have been, in a military sense, annihilated before the middle of September. What preserved it was the immediate decision undertaken upon that Monday night to proceed, in spite of the fatigues that were already felt after the first day's retreat, with a retirement upon the south-west, and to proceed with it as vigorously as possible. It was not yet daylight upon the morning of Tuesday, August 25th, when the move began. The Field-Marshal counted justly upon some exhaustion in his immensely superior enemy, especially in those troops of his upon the west (the 2nd German Corps) which had to perform the heavy marching task of getting round the end of the British line. This element, combined with the considerable distance which the British marched that morning, saved the army; though not until another week of almost intolerable suffering had passed, and not until very heavy losses indeed had been sustained. The great Maubeuge-Bavai road, which is prolonged to Eth, and which was, roughly, the British front of that night, was cleared shortly after sunrise. A couple of brigades of cavalry and the divisional cavalry of the 2nd Corps covered the operation on the centre of the right, in front of the main body of the 2nd Corps, while the rest of the cavalry similarly covered the exposed western edge and corner of the line.