The three armies combined numbered 384,000 men.
There were still the Ist, IId, and IVth Corps, 100,000 men; but they were not at first included, as the means of railway transport were engaged for twenty-one days.
The 17th Division and the Landwehr troops were told off to defend the coast. During the night of July 16th the Royal order for the mobilization of the army was issued, and when His Majesty arrived in Mayence, a fortnight later, he found 300,000 men assembled on and in front of the Rhine.
In his plan of war, submitted by the Chief of the General Staff, and accepted by the King, that officer had his eye fixed, from the first, upon the capture of the enemy's capital, the possession of which is of more importance in France than in other countries. On the way thither the hostile forces were to be driven as persistently as possible back from the fertile southern states into the narrower tract on the north.
But above all the plan of war was based on the resolve to attack the enemy at once, wherever found, and keep the German forces so compact that a superior force could always be brought into the field. By whatever special means these plans were to be accomplished was left to the decision of the hour; the advance to the frontiers alone was preordained in every detail.
It is a delusion to believe that a plan of war may be laid for a prolonged period and carried out in every point. The first collision with the enemy changes the situation entirely, according to the result. Some things decided upon will be impracticable; others, which originally seemed impossible, become feasible. All that the leader of an army can do is to get a clear view of the circumstances, to decide for the best for an unknown period, and carry out his purpose unflinchingly.
The departure of the French troops to the frontier, before they were thoroughly prepared for service in the field, which is a very serious step to take, was evidently ordered for the purpose of surprising the German army, with the forces immediately at command, and thus interfering with the formation of their advance. But, in spite of this, the German commanders did not deviate from their purpose of massing their armies on the Rhine and crossing that river. The railway transport of the troops of the IId and IIId Corps, however, was to end at the Rhine; thence they were to march on foot into the cantonments prepared on the left bank of the river. They moved in echelon, advancing only so many at a time as would make room for the Division behind them, as far as the line marked by the towns of Bingen, Dürkheim, and Landau.
The final advance towards the frontier was not to be undertaken until the Divisions and Corps were all collected, and provided with the all-necessary baggage train; and then proceed in a state of readiness to confront the enemy at any moment.
The assembling of the First Army appeared to be less threatened, as its route lay through neutral territory, and was protected by the garrisons of Trèves, Saarlouis, and Saarbrücken, the German outposts on the Saar.
The First Army, 50,000 strong, was concentrated at Wadern, in the first days of August. The Second Army, which meanwhile had been increased to a strength of 194,000 men, had pushed forward its cantonments to Alsenz-Günnstadt, at the termination of the Haardt Mountains, a position which had been thoroughly reconnoitered by an officer of the Staff, and where the troops might boldly await an attack.