On the night of July 16th the Royal order for mobilization was issued, and when his Majesty arrived in Mayence fourteen days later, he found 300,000 men assembled on the Rhine and beyond.
The plan of campaign submitted by the Chief of the General Staff, and accepted by the King, proves that officer to have 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 provinces into the more confined background to the north. But beyond everything the plan of campaign was based on the resolve to attack the enemy at once, wherever found, and keep the German forces always so compact that this could be done with the advantage of superior numbers. The specific dispositions for the accomplishment of those objects were left to be adopted on the spot; the advance to the frontier was alone pre-arranged in every detail.
It is a delusion to imagine that a plan of campaign can be laid down far ahead and fulfilled with exactitude. The first collision with the enemy creates a new situation in accordance with its result. Some things intended will have become impracticable; others, which originally seemed impossible, become feasible. All that the leader of an army can do is to form a correct estimate of the circumstances, to decide for the best for the moment, and carry out his purpose unflinchingly.
The advance of the French troops to the frontier, while as yet imperfectly mobilized, which was an extremely hazardous measure in itself, was evidently with the intent of utilizing the temporary advantage of having a superior force at immediate disposition by taking at unawares the German armies in the act of developing their advance-movements. But, notwithstanding, the German commanders did not deviate from their purpose of promptly effecting this first advance in front of the Rhine. The railway transport of the Corps of the IInd and IIIrd Armies, however, ended at the Rhine; thence the troops marched 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 body in rear, in the first instance to the line Bingen-Dürkheim-Landau. The farther advance towards the frontier was not to be undertaken until the Divisions and Corps were all assembled, and provided with the necessary trains; and then they were to march forward in a state of readiness to confront the enemy at any moment.
The massing of the Ist Army appeared to be less threatened, because its route was protected by neutral territory, and was covered by the garrisons of Trèves, Saarlouis and Saarbrücken, the German outposts on the Saar.
The Ist Army, 50,000 strong, was concentrated at Wadern, in the first days of August. The IInd Army, which meanwhile had been increased to a strength of 194,000 men, had pushed forward its cantonments to Alsenz-Günnstadt, at the farther base of the Haardt Mountains, a position which had been thoroughly inspected by an officer of the General Staff, and where the troops might confidently await an attack. The 5th and 6th cavalry Divisions were reconnoitring the country in front. The IIIrd Army was still assembling on both banks of the Rhine.
The French so far had made no serious attempt at Saarbrücken; Lieutenant-Colonel Pestel, with one battalion and three squadrons, was able successfully to withstand their petty attacks. It had meanwhile been observed that the hostile forces were moving farther to the right, towards Forbach and Bitsch. This seemed to indicate that the two French Corps known to be about Belfort and Strasburg, might purpose crossing the Rhine and marching through the Black Forest. It seemed therefore all the more important that the IIIrd Army should be set in motion as early as possible, for one thing to protect the right bank of the Upper Rhine by an advance on the left; for another, to cover the left flank of the IInd Army during its advance.
A telegraphic order to that effect was despatched on the evening of July 30th, but the Head-quarters of the IIIrd Army wished to wait for the arrival of the VIth Corps and of the trains. Whereupon, regardless of this delay, the IInd Army was put in march towards the Saar, where the French were beginning to be active.
The time had gone by when they might have taken advantage of their over-hasty mobilization; the inefficient condition of the troops had paralyzed every attempt at activity. France had been long waiting for the news of a victory, and something had to be done to appease public impatience. So, in order to do something, it was resolved (as is usual in such circumstances) to undertake a reconnoissance in force, and, it may be added, with the usual result.
On August 2nd three entire Army Corps were set in motion against three battalions, four squadrons, and one battery in Saarbrücken. The Emperor himself and the Prince Imperial shared in the enterprise. The IIIrd Corps advanced on Völklingen, the Vth through Saargemünd, the IInd on Saarbrücken.