The secret of success in so bold an undertaking lay in the corps d’armée system. In the days of Turenne and Marlborough, the largest formation in common use was the brigade, and it was not until the middle years of the eighteenth-century that even the division made its appearance; it was the subsequent grouping of several divisions into corps containing elements of all arms that made Napoleon’s plan feasible.
The corps system had already proved its value in a simplified form during the Marengo campaign of 1800, when the advantages of strategic mobility it conferred were tested for the first time on a reasonably large scale. In 1805, the perfected system was to enable Napoleon to move 226 battalions, 233 squadrons, 161 artillery and sapper companies and a general staff of 1,108 officers, or a grand total of 210,500 men including 29,500 cavalry, together with 396 guns (including 58 twelve-pounders, 146 eight-pounders and 52 canons de six), dragged by 6,430 horses, over a distance of more than 200 miles in the surprisingly short time of thirteen days. The corps into which this vast armament was divided varied in size according to their proposed roles, ranging from Soult’s 41,000 to Augereau’s 14,000 men—a circumstance that greatly facilitated the maintenance of field security. The enemy might learn the approximate positions of the corps d’armée on a certain date, but this information in itself would give little indication of the battle strength of the various formations; furthermore, Napoleon’s habit of altering the establishment of his major units in midcampaign, even creating new corps as the need arose, also served to delude enemy intelligence.
To ease the supply problem and avoid congestion on the roads of central Europe, each of the corps* was routed along an independent line of march, ensuring that only a single major formation would have to live off the countryside in any given area. However, it was carefully arranged that the corps should march within one or at the most two days’ supporting distance of one another. Each corps contained a division of light cavalry to screen its movements.
Notwithstanding the assistance afforded by this flexible disposition of the bulk of the army, a vast number of preparatory tasks and administrative arrangements had to be accomplished before the troops could cross the Rhine and enter into active operations. Murat was given the task of organizing 22,000 troopers into the cavalry reserve, charged with a variety of duties which included the making of the initial feint attack, the protection of the army’s communications and the harassment of the enemy’s line of retreat, but above all, the creation of a screen between the main army and its adversaries. Marmont was placed in command of the artillery, much of it designated by Napoleon to form a reserve for employment in battle only. These two formations were innovations of the greatest importance and were destined to play vital roles in the unfolding events of the campaign.
As speed and surprise were vital considerations, the Emperor made drastic reductions in the “tail” of administrative units. Revolutionary armies had long been accustomed to “living off the countryside” through necessity, but the system of local requisitions had now become an established feature of logistical support. In the interests of maximum mobility, the supply trains of the Grande Armée were issued with four days’ rations of bread and as many more of biscuit, to be distributed only if a major action was imminent. Even so, 3,500 four-horse wagons had to be requisitioned to supplement the regular supply services. If he was somewhat unconcerned about his men’s stomachs, Napoleon was determined to protect their general fitness in other respects, and personally intervened with the quartermaster’s department to ensure that every soldier was issued with two pairs of boots and a new cloak of warm material.
The orders sent to Marshal Massena in North Italy left no doubt about the great importance the Emperor placed on the activities of the French forces stationed in the subsidiary theater. After stressing the need to keep the Austrian troops in the region too busily occupied to allow any transfers to the Danube front, the Emperor added a piece of sound strategical advice: “I recommend my brave Army of Italy to you, but do not allow them to fight in detachments. Eighty thousand Austrians, drawn up as they are, are no match for 50,000 of our soldiers provided they stay close together.”3
Napoleon at first hoped that the Grande Armée would be able to cross into German territory on September 17, but this forecast proved over-optimistic. After delaying his own departure from Boulogne until September 3 to disguise the initial moves of his men, Napoleon reached Paris on the 5th to find trouble awaiting him. In the first place, his financiers were compelled to report a full-scale economic crisis. For one reason or another the tax yield for the previous twelve months had been disappointing, and in consequence there was little ready cash available in the treasury to cover either the high military expenses already incurred or to underwrite the requirements for the new campaign. Three valuable weeks sped by before the nation’s monetary affairs were once again in reasonable order. Nor were financial affairs the only problems faced by Napoleon during this time. To complete the ranks of the Grande Armée, it had proved necessary to call up 80,000 conscripts one year in advance of the legally liable call-up age of twenty years; this move met a surprisingly united hostile reaction from both populace and legislature alike, and Napoleon was compelled to rush through the necessary legislation by means of a decree senatus consultum, without having recourse to the Assemblies.
The Campaign of 1805 on the Danube
In the meantime, first reports were reaching the Emperor from the Rhine; on the 13th he learned, by way of the excellent military semaphore telegraph stations linking Paris with the frontier, that General Mack had crossed the River Inn and was advancing on Munich. A week later Murat’s scouting parties announced that at least part of this army had reached Ulm but that there still were no signs of the Russians. On receipt of these tidings Napoleon knew that the moment for action had come. Mack was obligingly blundering into the trap prepared for him; it only remained to slam the door behind him. The Emperor accordingly ordered that the army should cross the Rhine on the night of September 24-25 and commence its broad enveloping movement. Leaving Paris with his household (the Empress Josephine accompanied him for the first few days of the journey), Napoleon traveled rapidly eastward to rejoin his forces; the 25th found him at Nancy, and the following day he was at Strasbourg, ready to assume personal control of the unfolding operations.
The Gregorian calendar was ten days ahead of the Julian system.
Seven line (to include Augereau’s command), one reserve cavalry and one general reserve corps (August 1805). See Appendix for a detailed order of battle.
35
STRATEGIC TRIUMPH—ULM
Twenty-four hours earlier, the first troops had crossed the Rhine and very soon the deception plan was in operation. Issuing out of Strasbourg, Lannes’ Vth Corps and part of Murat’s cavalry reserve (between them totaling 40,000 men) advanced boldly into the defiles of the Black Forest—led by Baraguey d’Hilliers’ division of dragoons—toward the initial objective of Freudenstadt. As was intended, these diversionary moves drew Austrian troops still further to the westward, and a relieved Emperor could write to Talleyrand on the 27th: “Everything goes well here; the Austrians are in the Black Forest defiles; God will it that they stay there! My only fear is that we shall scare them too much. The next fortnight will see many things happen.”4
In the event there was little need for anxiety. Mack remained as if hypnotized as the main French army swept toward his rear. For several days he was in complete ignorance of the size of the fate bearing down on him, for a combination of the wooded hills of the Black Forest and the eastward running line of the Jura Mountains concealed the magnitude of the French movement, while Murat’s cavalry reserve and the corps’ light cavalry divisions maintained an impenetrable screen between the two armies.
The French march proceeded with almost mechanical precision under conditions of fine autumn weather. On October 1, Napoleon reached Ettingen and met the Duke of Baden; next day he pressed on for Louisburg where he, obtained a promise of a
id from his ally, the Elector of Württemberg. On the 3rd, the leading elements of the army had reached a line between Stuttgart and Ansbach, while Lannes and d’Hilliers pressed forward through Pforzheim to join Ney’s VIth Corps at Stuttgart in order to create a strategic flank and a pivot around which the more northerly corps could swing for the swoop toward the Danube. The lines of communication snaked safely back from Stuttgart and Spire toward Durlach and thence to Strasbourg.
The relatively smooth progress of the march was a triumph of careful planning and staff work. Morale remained extremely high as the columns hurried onwards, the soldiers joking that their Emperor was creating a new weapon of war out of their legs to replace their bayonets, but all too soon the fine weather broke and the gaiety of the earlier days was replaced by a damp and hungry dejection as weariness increased and forage became more difficult to obtain. Nevertheless, there were surprisingly few cases of desertion. Marmont’s IInd Corps lost only nine men as far as Würzburg when a figure of 300 would have been accepted as “normal wastage.”
The length of the daily stages varied between 12 and 40 kilometers according to the requirements of the overall plan, but most units averaged about 30 kilometers a day. The troops formed column between four and six in the morning, and the day’s journey was habitually over by noon, leaving the afternoon free for foraging and the evening and night for rest. This feature of the advance bore a close resemblance to Marlborough’s arrangements for his march in 1704. In an attempt to ensure a fair distribution of local food resources, each division was allocated a camping and foraging area some 20 kilometers square. On the march, the infantry and cavalry advanced in two files along the roadsides, leaving the center free for the heavier equipment, the generals’ carriages and the guns. Every brigade had a band which was divided into three sections, playing at the head, center and rear of every column, each taking up the drumming in turn. Every hour a five-minute halt was authorized, during which the musicians were expected to strike up, and the last half hour of the appointed day’s march was also made to the accompaniment of music. A division of 4,000 infantry occupied four kilometers of road, allowing for an interval of 100 paces between each battalion, and a cavalry regiment took up 1,000 yards of roadway. The rate of march was in the region of three miles an hour, and it was found that this could be maintained day after day with little trouble.
A considerable number of letters from les grognards have survived from this period and give an interesting picture of life in the ranks. Corporal Jean-Pierre Blaise of the 108th Regiment of the Line described the progress of his unit in an account written some years later from notes jotted down at the time.
We passed in revue before the Emperor on the 8th Fructidor of the Year 13.* The same day we learned with joy that we were leaving the coast where we had been camped for two years, and were going to make war in Germany. I can assure you that these tidings pleased us greatly for the men had suffered much from boredom during the army’s long sojourn besides the sea; now, commanded by the Emperor, we felt certain that we would march to victory. The first division of our army corps set out on the 9th, followed by ourselves on the 11th. There is nothing worth telling you about our journey as far as the Rhine, which we crossed on the 5th Vendemaire of the Year 14 without seeing the enemy. Perhaps I should mention that when we set out we thought we were going to Haguenau where we would be allowed a period of rest. We left the enemy on the right bank so as to cross the Rhine at Mannheim; on the 4th, every man had been issued with cartridges and ordered to leave all unnecessary personal effects at the depot at Frankenthal, being advised to carry as little as possible. After crossing the Rhine we were only billeted on the local people twice. The speed of our march made it impossible for supplies to keep pace with us, and so we were often short of bread in spite of all the efforts of our commanding general, Marshal Davout; and when we did receive some it was so bad that it was inedible…. Fortunately, it was the height of the potato season, and they were plentiful in our area. How many times did we ruin the hopes of the villagers! We pillaged from them the fruits of an entire year’s work. However we were, as you might say, forced to do so….5
On October 2, the army began the wheel to the south, and the front steadily narrowed from a width of 120 kilometers on the Ansbach-Stuttgart line to 60 kilometers by the time the troops reached the Danube between Ingolstadt and Donauwörth. The movement resembled a door swinging on its hinges. On the outer edge, with furthest to go, marched the corps of Marshals Bernadotte and Marmont, strengthened by the Bavarian detachment, the former indifferently violating neutral Prussian territory by marching through Ansbach in the interests of speed, an act that was to have interesting repercussions in due course; in the center advanced Soult and Davout with the two largest formations; on the right, forming the pivot, were Ney, Lannes, the Imperial Guard and Murat’s reserve cavalry. At this juncture the weather became bitterly cold—rain, sleet and even snow falling continuously—but this did not prevent the army reaching the Plain of Nördlingen by the 6th; the appointed crossing-places over the Danube, Münster and Donauwörth, Neuburg and Ingolstadt, were now within range.
The Maneuver of Ulm, September 25 to October 21, 1805
Meanwhile, what of the enemy? Although General Mack was now aware of the broad developments, Archduke Ferdinand seemed incapable of comprehending events; the rabbit remained hypnotized by the snake. Several courses of action were open to them. Before Napoleon reached the Danube they could have launched a tactical offensive against one of the Grande Armée’s southernmost columns, making full use of the superior Austrian cavalry to strike a rapid blow and then retire before the supporting French corps had time to materialize. Such a course of action would have slowed the French rate of advance. At the very least the Austrians might have taken serious steps to defend the crossings over the Danube, Lech, Isar and Inn, and thus prepare to fight a delaying action to give Kutusov time to come up on the French flank. In the event, however, the mesmerized Austrian generals only ordered the concentration of their outlying detachments in the vicinity of Günzburg to the east of Ulm.
So effective were Napoleon’s security measures that his opponents had little accurate idea of what was taking place. All mention of the move was rigidly excluded from the French press; the frontiers were sealed to prevent leakage of news; even the corps commanders were entrusted only with a minimum of information in case a set of captured orders might reveal the complete plan. Above all, it was the effective screening operations of Murat’s reserve and the corps cavalry divisions coupled with the speed of movement maintained by the entire army, that confused the enemy.
With the Danube in sight, the French corps took up positions for the crossing. Half the army was to pass the river to the east of its junction with the Lech tributary so as to sever Mack’s communications and turn his flank from the north, while the remainder crossed to the west of the confluence to deny the Austrians the use of the Lech bridges themselves. On the night of October 6-7, General Vandamme seized the Donau crossings and Murat took possession of Münster. During the following twenty-four hours Soult’s corps passed through Donauwörth, and Murat sent one division across the Danube to seize the bridge over the Lech at Rain. The same day, Davout reached Neuburg. Napoleon now anticipated that Mack would come rushing eastward in headlong retreat, and planned to destroy him in detail. “My intention, when we meet the foe, is to envelop him on all sides,”6 he wrote to Soult on October 3.
To trap the enemy in this way involved closing all possible avenues of escape. Now that Napoleon was in the act of crossing the Danube, General Mack could attempt one of three things. He might try to retire into the Tyrol, but by so doing he would obviously be forced to abandon his mission of covering the approach of the Russian armies; secondly, if he were bold enough, the Austrian commander might launch an immediate counterattack along either the north or south bank of the Danube designed to catch the French halfway over the river and annihilate them in detail as they crossed, or at least for
ce his way back toward Vienna; thirdly, he could mount delaying actions along the successive river lines, trading space for time. Napoleon felt confident that Mack would not try to retreat along the north bank of the Danube, for such a move would expose the road to Vienna and at the same time isolate the Austrians from their southern depots. Consequently, the Emperor felt he had little reason to fear for the security of his own lines of communication, which were protected by a total of 16,000 Hessians, Würtemburgers and Badeners provided by his allies. However, as additional security measures, the main communications were rerouted from Spire to Nördlingen, and two divisions of cavalry (d’Hillier’s and Bourcier’s dragoons) and one of infantry (General Gazan—detached from Marshal Lannes’ corps), were allocated to strengthen the communication troops for the time being. These forces were within easy supporting distance of Ney’s corps, which was now moving along the left bank of the Danube.
Little time was lost devising measures to block the remaining avenues open to Mack; the Emperor ordered the setting-up of a center of operations at Augsburg, and spread his corps around this center in a closely-knit web. Soult’s IVth Corps was routed toward Landsberg and thence westwards to Memmingen to seize the main Austrian depots and close the Tyrolean escape route up the river Iller. To dominate the main road leading from Ulm through Gunzburg towards Augsburg, Napoleon despatched Murat and Lannes along the south bank of the Danube to act in conjunction with Ney to the north of the river. To guard against the possibility of intervention by the Russians from eastward (Napoleon had no accurate information at this stage as to the exact whereabouts of Kutusov), Bernadotte and Davout were ordered to set up a “zone of security” around Munich, with the lines of the rivers Isar and Lech available to them as defensive positions should the Russians appear in strength. Lastly, in the center of the web sat the spider; Napoleon retained the Guard and Marmont’s corps in the vicinity of Imperial Headquarters at Augsburg to serve as a strategic reserve. This plan allowed for every possible eventuality. Every corps was within 48 hours’ supporting distance of at least two neighbors (with the possible exception of Ney) and could therefore concentrate on any threatened sector; at the same time, the net was spread before General Mack’s army, and whether he rushed into it or stood his ground, there was no easy way of escape left open to him. Napoleon was evidently proud of his achievement, and this is reflected in the Army Bulletin of October 7: “The enemy advanced into the passes of the Black Forest where he planned to position himself and hold up our penetration. He hastily fortified the Iller, Memmingen and Ulm. However, our patrols which are scouring the countryside assure me that he has abandoned his plans, and that he appears to be gravely worried by our moves which are as unexpected as they are novel. This great and vast movement has carried us in only a few days into Bavaria, avoiding the mountains of the Black Forest, the line of parallel rivers running into the Danube valley and the inconvenience of a system of operations always threatened from the flank by the passes of the Tyrol; furthermore, it has placed us several days march in the rear of the enemy who has no time to lose if he is to avoid a complete disaster….”7
The Campaigns of Napoleon Page 50
