Frederick Invades Austria a Second Time; Siege of Olmütz I

On March 15, 1758, the king marched from his winter quarters in Breslau. He started on the third campaign of this conflict, waiting until the frosts were gone and the cold winter winds had subsided. The headquarters was moved to Kloster-Grüssau and the army was encamped between there and Landshut. Frederick’s job was to keep the whitecoats quiet in Bohemia while his army descended on Schweidnitz to reclaim that fortress from its enemy garrison. This he meant to accomplish before the time of normal campaigning, and before the cautious Daun could interfere with his maneuver.

This was a bold plan, and very risky as the king’s plan placed great reliance on Daun being slow and methodical. The Prussian magazines at Jauernick and Sabischdorf were prepped to supply the needs of the forces preparing to besiege Schweidnitz. The bluecoats had been loosely investing the fortress during the winter layover. The storming of Schweidnitz was an essential preliminary to another invasion of the Austrian Empire. The king had already decided to carry the fight into the very heart of his greatest enemy for the second time in as many campaigns.

In any case, the elimination of the last major body of Austrian troops in central Silesia would give Frederick’s largely new troops the confidence they needed to face the enemy massing to their front. During the winter, Maria Theresa had been engaged in strengthening both the number and preparedness of the Austrian army. In addition to the effort to refine the command structure of the army, the numbers of men needed replenishment.

The garrison of Schweidnitz had utilized the time given to build up the fortifications there to make any Prussian attempt to retake it into a major task. Yet, the men could not help but be affected by their isolation from the main Austrian lines. Of the original 8,000 men, only 5,500, some of those of questionable quality, remained available, and even most of these men were somewhat demoralized from the degree of the Prussian successes, most notably Leuthen, the previous year. These latter were under Lt.-Gen. Franz Ludwig Thürheim and Major-General von Gröttendorf.

In the final days of March, Frederick reached the vicinity of Schweidnitz and began deploying his army for the siege. The fall of the place seemed imminent. Rossbach had shaken the French, so much so the king felt he may not have to deal with them until perhaps mid-summer. The Austrians, still smarting and shaky from Leuthen—in spite of Maria Theresa’s best efforts—would not be able to launch any offensive operations on a major scale for most of the year. As for the Imperialists, they were still hungover from Rossbach. Neither the Swedes nor the Russians were as yet ready for marching. It was, in many ways, now or never for this second invasion of Austria. As per the old axiom, “First things first.” General Tresckow was given charge of the siege forces around Schweidnitz. He had nearly 10,000 men, 4,600 of whom were cavalry. This was by no means an overwhelming force.

Nonetheless, the Prussians made steady progress towards the siege. The siege guns were brought up, and, in the first two days of April under a soaking front of rain, the first parallel of the siege lines were completed. The whitecoats, under the miserable conditions, did not discover the Prussian effort until it was a done deal. The bluecoats made sure of having sufficient artillery in place to do the job. Forty-eight pieces of ordnance were employed by the Prussians altogether, including eight 24-pounders.

The weather was not very cooperative. Since the Austrians failed to detect the line until it was completed, by then nothing could be done about it. April 8, with Marshal Daun still deep in Bohemia, the first shots of the siege batteries opened on the fortifications. Galgen, as the main fortress, was heavily cannonaded day after day, and gradual progress was made, despite miserable weather conditions. The whole structure was intrinsically affected by its location. Schweidnitz was designed by “placing the main weight of the defence on a girdle of detached forts and lunettes.” This could only increase the suffering of the besiegers and the besieged alike. All of these factors made Frederick, who never favored siege operations under any conditions, want to wrap things up even more quickly.

In the meantime, operations elsewhere had begun. On the eve of the march towards Schweidnitz, the king detached two strong columns from the main army: (1) One, under Ziethen, was to take up post near Troppau; and, (2) The second, Fouquet to Glatz. Both of these detachments had the duty of sweeping away the remnants of the Austrian forces in southern Silesia and, more importantly, keep it clear. There had been no word of any activity from the vicinity of Marshal Daun and his still reforming army.

The irascible Laudon spent much time urging on the reluctant Daun to relieve Schweidnitz (a viewpoint which he shared with Chancellor Kaunitz), and he was kept busy with his light troopers engaged in isolated actions with detached bodies of bluecoats. Laudon here can certainly be commended for seeking bold action, but Marshal Daun was fully aware that his army was not ready to take on the very confident Frederick just yet. Especially after such a crushing defeat as had been inflicted on them at Leuthen.

Nevertheless, Daun left his winter quarters on March 13. He promptly moved on to Königgrätz. The marshal and his army were posted there even now, digging in with his vaunted defensive skills, as well as training troops and having even more equipment brought forward for the army. The agitated marshal still had the advantage, if nothing else, of superior numbers: 100,000 Austrians against the maximum of 70,000 Prussians he faced. If it had been his desire, Daun could certainly have proven to be a problem for Frederick’s plans. But the latter suspected his adversary’s slow, calculating character, and took a reasonable risk that nearly paid off. In the campaigns to come, Frederick would take many more risks with Daun as his chief enemy.

The Austrian commander had guessed (correctly) that the king meant an invasion of the Austrian Empire again this year. Daun was mistaken, though, in the route that invasion would take. The Austrians had spent the winter preparing the passageways into Bohemia for the Prussian intruders. Impressive defensive posts had been prepared—posts that would not be needed. This was especially ironic since the Austrians did a much better job of preparing for a possible Prussian invasion of Bohemia in 1758, when it did not occur, than they had done in 1757, when it did.

The Austrian army itself had been steadily reinforced during the winter layover by new blood, and at his impressive camp at Skalitz (occupied on April 19), Daun had carried forward heavy training exercises until the men were becoming proficient in their trade. Unfortunately for them, the Prussian king had decided to bypass Bohemia this time around, where Prague alone was still the lone Austrian vital point, and instead proceed directly into Moravia. Daun cooperated by not taking his army past Königgrätz and interfering with the Prussian siege of Schweidnitz. Rising star Laudon did his best, to no avail, to persuade the marshal to move to try to thwart the Prussian effort to retake Schweidnitz which would enable them to drive away the last Austrian toehold in Silesia.

The king considered it too risky to make further moves while Schweidnitz remained in Austrian hands. The fact Daun refused to help the garrison presaged what was to come. But there was some basis for this attitude. There were still many in the army who could not look past 1757. While Daun waited at Königgrätz, the impressive fortifications of Schweidnitz fell. After a week of steady progress, Tresckow and Colonel Johann Friedrich von Balbi, the chief engineer, both suggested that the place was ripe for the storming. Balbi saw to it that the besieging troops, which were hardly more numerous than the defenders, were kept supplied with meat and beer. As for the cost, he begged the king “not to look at the expense.” There was also some urgency to wrap the business up. With this thought in mind and purpose, the king summoned Marshal Keith to take over the direction of the besiegers. Accordingly, evening of April 15, the bluecoats made ready and, that night, assailed the Austrian lines.

Meanwhile, though, Thürheim’s batteries had been positioned in order to enfilade the enemy’s siege lines, beyond the town walls. On April 13–14, the Austrian ordnance was pulled back to the town walls, under the increasing Prussian pressure mounting against the works. About 0200 hours on April 16, bluecoat grenadiers, of Grenadier Battalion 21/27 (Colonel Bernhard Alexander von Diringshofen), Kreytzen’s 28/32 Grenadiers, and 41/44 (Beneckendorf), stormed forward. Galgen was taken, and so swiftly that the assaulting column lost 85 men. This was the crisis of the siege. With his best post gone, the Austrian commander, General Thürheim, surrendered before dawn (April 16), forestalling a general assault. The loss to the Austrians was again great: 51 brand-new guns, considerable monies and the garrison. The loss of the latter was approximately 4,841. The Prussians lost 102 men killed, and 261 wounded. Fortfeiting so many veterans in the garrison was a serious blow for Austrian fortunes, especially when we realize the hemorrhaging among both the rank-and-file and the officers going on just then.

This enterprise now out of the way, Frederick proceeded at once with the planned invasion of the enemy’s territory. For this new incursion, the army was to be divided into two columns: one, under Prince Henry, who was given charge in Saxony. Henry’s task was to move in the manner of a support rôle. The rest of the army, that section remaining with the king, was to perform the actual invasion. Henry was to threaten the left of Daun’s army in northern Bohemia while Frederick’s men were to march southeast across the front of the enemy force to Neisse and Jägerndorf. They were probing for Moravia, and the real destination, the city of Olmütz. The latter lay about 100 miles from the nearest Prussian frontier. Austrian Croats, Tolpatches, and Pandours were thick in the intervening country.

Daun had a large body of men put into position at Trautenau, under General Buccow, while Arenberg hitched into Nachod. The irregulars of Laudon (some 5,000 strong) stayed in close touch at Lewin, but there was certainly nothing special about the Austrian dispositions. Daun was clearly interested in covering the Austrian realm against Prussian invasion. Incidently, by the beginning of the new campaign, General Lacy was no longer in the field. He was back in Vienna, busy organizing and refining the very first office of an Austrian Chief of Staff. Lacy displayed an immediate bent towards meticulous planning, and careful consideration, although we should be careful not to use the term “bean counter,” which Lacy indubitably was not. Lacy’s contemporary on the staff, General Johann Anton Baron Tillier, helped in this build-up. The contributions of a well-run general staff would reap rich benefits for the whitecoats for the rest of the war and beyond. It is worth mentioning that Lacy was also personally involved in parts of the campaign in the field.

Meanwhile, Frederick’s intentions were plain; to his generals. He planned, once Olmütz was in Prussian hands, to press southward upon Vienna. Once there, he could threaten the very heart of the Austrian Empire. An outright occupation or siege of the Austrian capital might serve to induce one or more of the allies to seek peace. All being prepared, Frederick moved out on April 19. His march was confused deliberately, for the benefit of Daun, and the Prussians proceeded on Neisse and Jägerndorf. A six-day march (April 19–25) brought them to the frontier of Moravia. To make his intentions less clear, Frederick marched his army in two distinct columns.

In this way, the Prussians were able to slip past the formidable Austrian lines at Königgrätz with relative ease. At Troppau, the bluecoats turned southward, causing Daun to suspect Frederick might be heading into Bohemia from the east. The marshal kept his men idle until April 27, while Frederick took his men on their journey. The Prussians paused at Märisch Neustadt. General DeVille had thrown roving patrols out in the area. When the Prussians put in their sudden appearance, DeVille pulled up stakes and withdrew with some haste to Prossnitz. Without further ado, the king moved towards Prossnitz in a manner which threatened to bring DeVille to battle. Simultaneously, he detached Commander Werner—with two full regiments of hussars—to go occupy an enemy magazine at Olschan. The king’s move towards DeVille was interpreted by the latter (with some exaggeration) as a serious threat. The Austrian commander decided once again that discretion was the better part of valor, and promptly fell back upon Prödlitz. He withdrew, leaving behind 300 hussars at Olschan. The Prussians nabbed 40 as prisoners (May 5), and pressed on to Tafelberg, where the Austrians had a small garrison.

With Prossnitz vacated, Prince Eugene of Württemberg took a large command (about 8,000 men), and took up quarters there. With the arrival of General Fouquet at Krenau (May 16), Frederick rose from Littau and marched with some 10,000 men to link up with Eugene thereabouts. The latter had gradually moved from Prossnitz towards his new post, under close observation of Austrian reconnaissance patrols. At Prossnitz, the bluecoats encamped, with their headquarters at Schmirsitz. Fouquet held command of the Prussian center in this new post. The Prussian guns were placed on some of the local high ground; just in case the Austrians tried something daring. Such was not the case, and the foe did not bother the Prussian camp.

With nothing stirring on Daun’s side of things, Frederick decided to step into the rôle of aggressor again. He took a force of cavalry and rode through Prossnitz headed for another confrontation with DeVille, then ensconced at Prödlitz. DeVille one more time had no intention of staying put. He fled to Wischau. A Prussian effort at pursuit was effectively thwarted by Count St. Ignon. The latter repelled the pursuers at Driffitz, rather decisively. Locals rapidly carried the word to Vienna that DeVille’s men had scattered and that the enemy were now astride the road to the capital. This intelligence was incorrect. Still, it must have been patently obvious Frederick’s intentions were not directed at all towards Bohemia this time around.27 With all doubt thus removed, the king went to work out in the open. The various detachments of Prussians were immediately set in motion, with a siege of Olmütz as a short-term goal. The main force straddled the rises between Prossnitz and the Morave. General Fouquet threw a force into Glatz to stiffen the troops already there.

As for the second formation, Keith followed at a day’s distance behind. This separation was necessary because of the lousy road conditions as well as the quartering of the troops, which otherwise could have been a serious problem. Across the Morawa and Oder rivers and the little passes through the mountains, the invaders moved. Ziethen, with some 8,000 men, had been sent ahead, and detailed to keep the marching men screened from the enemy’s swarms of irregulars. Fouquet, who had charge of the provision trains and another 8,000-man force, staggered his convoys, under heavy escort, through the passes. The main army moved via Littau, Aschermitz, to Prossnitz—within 15 miles of Olmütz.

The Prussians were in Prossnitz by May 2–3. The news from other war fronts was encouraging and gave the king confidence that he would have the time he needed for his new mission. Ferdinand was preparing to carry the fight across the Rhine into France itself. There was no need to look for interference from that side this year at all for Frederick’s designs. General Dubislav Friedrich von Platen with a detachment was busy watching Fermor. January 16, the latter’s Russians had crossed the border into East Prussia, then, sweeping aside the feeble Prussian resistance, occupied Königsberg, forcing the inhabitants to swear a loyalty oath to Empress Elizabeth. However, there was little fear of a Russian movement against Prussia’s vitals until summer at least, given the state of their army’s supply problems and other difficulties.

As for Henry, his army of 32,000 men was even then in southern Saxony watching the Imperialists.30 Until he received word that Olmütz was in Frederick’s hands his primary purpose would be the defense of Saxony. Prince Henry was engaged in sending raiding parties deep into Bohemia and trying to keep Daun’s attention diverted to that province, and thus away from Moravia.

From the Northern Front, the news for the Prussians was still good. Although they remained some 15,000 strong, the Swedes had been held back from advancing by the muddy roads of Pomerania and the capable defense of Dohna. The latter held the shoreline against them, except at Stralsund. Now the spring thaw had come, but there was no effort to advance by the Swedish army. The latter’s chronic problems included the aged commander, Field Marshal Gustav Friedrich Graf von Rosen.

Back at the Southern Front, Daun had felled almost a whole forest to fortify and strengthen his post at Königgrätz, his defenses being so elaborate that it is no exaggeration to say Frederick might have found his task of invading Bohemia that year was impossible, had that been his design. Daun, nothing daunted, “refused to play the rôle assigned to him in Frederick’s plans.” When word arrived of the king’s advance into Moravia, the Austrians rose and sped out of Königgrätz eastwards to blunt his advance and save an important magazine—at Leutomischl—from the enemy’s clutches. Daun wasted no time, performing a direct march, as the Prussians had finally made their intentions clear. Frederick had a distance of some 150 miles, Daun only a little more than half that far. But the Austrians would not reach Leutomischl until May 5. Once there, Daun intended to take post, shielded by ever present thick bodies of Croats and Pandours.