For five days and nights the battle raged about the entrenched crescent of the Nancy hills, with fiery wings outspread to Gerbéviller on the south-east, and Rozières on the north-west. No more dreadful struggle can be recorded. The German effort ceased on the night of September 9; and on the 11th the general withdrawal to the old frontier began. Like Foch, Langle, and Sarrail, Castlenau had won through by the narrowest of margins; but his, pre-eminently, was a victory of foresight and preparation. With all their power of heavy artillery (and here the resources of Metz and Strasbourg were at hand), it is remarkable that the German Staff never attempted to repeat in Lorraine the _coup_ of Liège. As the French respected Metz, they respected Verdun; and the manœuvre of the double approach to Toul, from east and west, proves their fears. These were, as we now know, well justified. “It is certain,” says Freytag-Loringhoven, “that the old-fashioned fortresses are worthless, and, moreover, that the earlier notion, handed down from the Middle Ages, that positions have to be secured by means of fortresses, must be discarded.... But it will not be possible to dispense with certain previously prepared fortified points at places where only defensive tactics can be employed. The fortifications of the French eastern frontier, above all Verdun and the Moselle defences, have demonstrated how valuable these may be.... It is a question of constructing not a continuous system of fortifications, but a succession of central points of defence, and this not in the shape of fortified towns, but of entrenchment of important areas” (pp. 64–6). And again: “The intention was to effect an envelopment from two sides. The envelopment by the left wing was, however, brought to a standstill before the fortifications of the French eastern frontier, which, in view of the prompt successes in Belgium, it had been hoped to overcome.... The defensive tactics of the chiefs of the French Army were rendered very much easier by the support these fortifications gave to their wing, as well as by the possibility of effecting rapid transfers of troops afforded by a very convenient network of railways, and a very large number of motor-wagons upon good roads (pp. 79–80)..... The war has proved that the assertion often made in time of peace, that the spade digs the grave of the offensive, is not correct” (p. 97).