When, in 1875, General Séré de Rivières was instructed to fortify this frontier, his plans provided for the construction of a line of forts along the Meuse Heights, capable of holding the bridges across the Meuse under gunfire, and thus enable the French Armies to concentrate behind the river near Neufchâteau. The three northern forts, therefore, faced the Meuse; the southern forts, viz., Gironville and Liouville, commanded both the Meuse and the Woëvre. The drawback to this plan was that the vast Woëvre Plain lying between Stenay, Longwy, Toul and Nancy, would be sacrificed in the event of a surprise attack. The importance of this possible loss was made all the greater by the discovery of coalfields in the Briey district. It was therefore decided that a number of battalions of Chasseurs should be garrisoned in the Woëvre towns. Moreover, the passing of the Three Years’ Military Service Bill made it possible to increase considerably the number of covering troops. In 1914, the Plan of Concentration provided for the grouping of the French Third Army in the Woëvre Plain. However, no permanent defences were erected. The fortress of Longwy, being isolated and of little military value, could not give effective protection. The German Government had on several occasions given the French Government to understand that they would disapprove the erection of fortifications in Woëvre. On the other hand, the Germans unceasingly strengthened their own frontier from Metz to Thionville, increasing the perimeter of the entrenched camp of Metz from 25 to 90 kilometres and erecting ten new forts. All the attacks against the Meuse Heights started from this vast entrenched camp, which, for four years, also furnished the German lines of St. Mihiel with troops. September 7, 1914, and the following days were particularly anxious ones for General Sarrail’s army which, resting as it did on Verdun, was to form the pivot of Joffre’s famous manœuvre (_see the Michelin Illustrated Guide_: “The Battlefields of the Marne, 1914”). HOW THE ST. MIHIEL SALIENT WAS FORMED First Attempt during the Battle of the Marne (_See map, p. 10._) A furious frontal attack was made on this army by the ex-Crown Prince of Germany, while at the same time it was taken in the rear, on the Meuse Heights, by the Bavarian Crown Prince. Had the latter succeeded in crossing the Meuse, Verdun would have become untenable; General Sarrail would have been forced to retreat southwards, and, as in this gigantic battle of the Marne all the armies were interdependent, such a withdrawal would have been felt all along the line, and Joffre’s plans for a strategical recovery would have failed.