The wars carried on by France beyond seas, essentially on behalf of financial interests, had consumed immense sums and had undermined the discipline of the army. Her army was by no means in thorough preparedness for a great war, but, in the temper of the nation, the Spanish succession question furnished an opportune pretext on which to go to war. The French Reserves were called out on July 15th, and, as if the opportunity for a rupture was on no account to be let slip, only four days later the French declaration of war was presented at Berlin.
One Division of the French Army was ordered to the Spanish frontier as a corps of observation; only such troops as were absolutely necessary were left in Algiers and in Civita Vecchia; Paris and Lyons were sufficiently garrisoned. The entire remainder of the army: 332 battalions, 220 squadrons, 924 guns, in all about 300,000 men, formed the Army of the Rhine, which, divided into eight Corps, was, at any rate in the first instance, to be under the sole direction of a central head. The Emperor himself was the fitting person to undertake this weighty duty, pending whose arrival Marshal Bazaine was to command the gathering forces.
It is very probable that the French reckoned on the old dissensions of the German races. Not that they dared to look forward to the South Germans as allies, but they hoped to paralyze their offensive by an early victory, perhaps even to win them over to their side. It was true that Prussia by herself was still a mighty antagonist, and that her armed forces were of superior strength; but peradventure this advantage might be counterbalanced by rapidity of action.
The French plan of campaign was indeed based on the delivery of sudden unexpected attacks. The powerful fleet of war-ships and transports was to be utilized to land a considerable force in Northern Prussia, which should there engage a part of the Prussian troops, while the main body of the German army, it was assumed, would await the first French attack behind the strong defensive line of the Rhine. A French force was to cross the Rhine promptly, at and below Strasburg, thus avoiding the great German fortresses; its function being, at the very outset of the campaign, to cut off the South-German army charged with the defence of the Black Forest, and prevent it from effecting a junction with the North Germans. In the execution of this plan it was imperative that the main body of the French army should be massed in Alsace. Railway accommodation, however, was so inadequate that in the first instance it was only possible to transport 100,000 men to Strasburg; 150,000 had to leave the railway at Metz, and remain there till they could be moved forward. Fifty thousand men in the Châlons camp were intended to serve as supports, and 115 battalions were destined for field service as soon as the National Guard should relieve them in the interior. The various Corps were distributed as follows:--