operation order "No. I." On the morning of Aug. 8, therefore, General Joffre, general-in-chief of the " Armies of the North- East," issued his specific instructions.
The French Offensive. The enemy, it seemed, had grouped his main forces in the region of Metz, in front of Thionville (Diedenhofen), and in Luxemburg, with some 12 divisions in Lorraine and Alsace and an undetermined force which included parts of 10 divisions in the Liege and Ardennes regions. This main force (Metz-Luxemburg) seemed to be pointing westward, but might equally well swing southward, pivoting on its forti- fications. The French armies were, consequently, to take the offensive which was to be a.s foudroyante as possible and with all forces in combination to seek to bring the enemy to decisive battle, resting their right flank on the Rhine. In order to ensure simultaneity and unison in the battle effort, it was laid down that the left wing armies might have to hold back, so as not to become involved in battle with German masses traversing the southern Ardennes or northern Woe'vre, or both, before the right wing had advanced and made effective contact with its opponents.
The I. Army (Gen. Dubail), composed as in "Plan 17," was, instead of merely cooperating with and flankguarding the II. (as in the plan), to become the main offensive element in Lor- raine and Alsace. Its VII. Corps, with a cavalry division, was to break into upper Alsace at once from Belfort, to drive back all forces it met, and, progressively reinforced by the three reserve divisions from Vesoul, to gain ground towards the fortified barrier Strassburg-Molsheim, destroying bridges and blocking- up bridgeheads on the Rhine as it advanced. The main body of the army, with a frankly E.N.E. direction, was to push towards the front Fenestrange (Finstingen)-Saarburg-the Donon, and to drive back its opponents on Strassburg and into lower Alsace.
The //. Army (Gen. de Castelnau), composed as in the plan, was now to play the part of auxiliary to the I. Its first objective was to be the front Delme-Salins-Dieuze, and its axis Chateau Salins-Saarbriicken. It was to flankguard towards Metz, and, moreover, to leave two of its five corps in the region of Toul at General Joffre's disposal.
The ///. Army (Gen. Ruffey), constituted as in the plan, was disposed in the Woe'vre facing Metz, and was to be ready either to counter-attack any German forces emerging from the Metz region or to take the offensive northward, with its left on Dam- villers, according to the situation. The two corps taken from Castelnau would probably be employed in concert with this army, either in repelling a counter-offensive from Metz or in a northward movement.
The roles to be given to the IV. and V. Armies were now defined more precisely. The IV. (Gen. de Langle de Gary) was to group itself between Argonne and Meuse, and the V. Army (Gen. Lanrezac) to condense between Vouziers and Aubenton, ready either (a) to attack any German army which traversed the Meuse between Mezieres and the line Damvillers-Mont- faucon or (b) to cross the Meuse themselves for the Ardennes- Arlon offensive. The II. Corps, hitherto the left wing of the pro- tective system and attached to the V. Army, was now added to the IV. Army and directed to hold firmly to the northern outliers of Verdun and the left flank of Ruffey's army. Beyond the flank of Lanrezac was the group of reserve divisions about Vervins; the cavalry corps operating E. of Mezieres and Montmedy was expected, if and when forced back over the Meuse, to take posi- tions about Marienburg and Chimay. The role of "Army W." was as yet quite unsettled, as also was that of the Belgians.
Such was the order which initiated the " Battle of the Fron- tiers," the opening of the World War on the western front. The intentions may be, and have been, criticized, but they are clear. The general offensive of the French right wing, fixed for the i2th day of mobilization (Aug. 14), was directed N.E. and E.N.E. into the Rhine lands behind Strassburg and Molsheim, with a subsidiary effort in Alsace which would make good a front facing Molsheim-Strassburg-Neu Breisach and the upper Rhine forti- fications, and, in case of success bringing the I. Army to behind Strassburg, besiege that fortress. The general offensive of the left was to be timed to coincide with the decisive phase of the
operations of the right, but placed according to the progress of the main enemy armies which were presumed to have their right flank not farther N. than Mezieres and their left flank on or in the fortified region Metz-Thionville.
But the possibility of arranging for the whole system to take its time from Dubail was made doubtful by a geographical factor the Meuse. Had the areas in which the IV. and V. Armies were to act formed a single region, it would have been different, but the critical question was how to get these two armies over the Meuse at the exact moment determined by events in Lorraine, which might also be the very moment at which the German masses from Luxemburg themselves arrived on the river. It was this disturbing factor, quite as much as any events to the N. of Mezieres, which governed the development of the French scheme. The details of this develop- ment, so far as concerns the left wing, are extremely complex and must be studied in the documents reproduced in F. Engerand's Briey, Joffre's Preparation de la guerre et conduits des operations, Lanrezac's Le plan de campaigne franfais, and the anonymous Le Plan XVII. (publ. Payot). Here only a summary can be given.
By Aug. 13, the eve of the day fixed originally for the general offensive, the order of Aug. 8 had ceased to apply integrally to the left wing. While Dubail and Castelnau were to advance on the front Donon-Saarburg-Saarbriicken, as previously indicated, and a new and stronger army of Alsace under Gen. Pau was to carry out that part of the scheme which the VII. Corps had just attempted with disastrous results (see FRONTIERS, BATTLES OF THE : section Alsace), Ruffey, de Langle de Cary and Lanrezac were directed according to a new scheme which was independent in time as well as place of operations in Lorraine. It was now clear that the German northern group was stronger than had been supposed, but the evidence of its intention to cross the Meuse above Liege and sweep round through the Belgian plain seemed less convincing than the probability of its descending southward, and the French Command, after much interchange of views with Lanrezac, decided to push part of the V. Army northward into the region W. of Givet as a defensive precaution, and with the remainder and the IV. and III. Armies to carry out a series of preparations which would suit either of two hypotheses. If the Germans moving westward through the Ardennes were well advanced, they were to be struck by an offensive against the front, flank and rear, as soon as they were thoroughly invoked in the crossing of the Meuse; if, as now seemed more probable, they were grouped with greater density in the northern and northeastern parts of the Ardennes, there would still be time for the V. and IV. Armies to advance before battle, not only over the Mouse, but also over the Lemoy and the lower Chiers. In that event the III. Army, which, with various mobile forces belonging to Toul and Verdun and the corps of the II. Army reserved to the general-in-chief by the order of Aug. 8, could assemble a considerable force, was to divide into a defensive group facing Metz and an offensive group which would aim northward, conforming to the right of the IV. Army, which would make good the lower Chiers; while the V. Army, holding defensively on the Meuse at Givet, was to reach the front Beauraing-Gedinne-Paliseul-Cugnon.
On Aug. 14, the offensive in Lorraine opened. Its progress was slow, but not marked by any untoward incidents up to Aug. 19. It was independent of events to the left of the Moselle except in so far as sorties might emerge from the S. and S.E. fronts of Metz, against which contingency the defensive group of the III. Army, the two reserved corps near Toul, and the echeloned left wing of the II. Army, were an adequate safeguard. On the other wing, however, obscurity still prevailed. Though Lanrezac was becoming more and more uneasy as to his left flank, and the Belgians, standing on the Geete line, called for support, nothing positive as to the German dispositions revealed itself, but on the evening of the I5th the veil was, partly at least, torn away. The part of Lanreza:'s army which was stationed in the angle of the Sambre and Meuse became engaged with a large force of the enemy at Dinant. This consisted in'reality only of cavalry and light infantry, but was estimated by the French commander, Franchet d'Esperey, as an army corps at least. At the same time, information came in tending to show that the Germans in the Ardennes included sixteen divisions. Moreover, the impression was formed both by Franchet d'Esperey opposing them and by the French cavalry commander skirting their southern flank, that the Dinant Germans were flankguarding a much more considerable force engaged in passing the Meuse below Namur; and Lanrezac energeti- cally insisted on the fact that such large enemy forces could not conceivably be intended to operate entirely on the right bank of the Meuse. A remarkable absence of troops, at the same time, was reported by the French aviators reconnoitring the Arlon region. Thereupon Joffre formed a new plan. The V. Army, except one corps (already attached to the IV.), and its two reserve divisions, reinforced by one of the reserve corps on the Moselle and by forces from Algeria, newly arrived, was to join the forces already in the angle of the Sambre and Meuse, and to cooperate with the Belgians and the British both of which armies now for the first time figured in the scheme of operations in attacking the front and outer flank of the German "northern" forces, while the IV. Army was to prepare to debouch from the front Sedan-Montmedy in the direction
