1757 - Siege of Schweidnitz

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Hierarchical Path: Seven Years War (Main Page) >> Sieges >> 1757 - Siege of Schweidnitz

The siege took place from October to November 1757

Description of Events

Prelude to the Siege

During the invasion of Silesia, taking advantage of the absence of Frederick II with part of the Prussian army confronting the Franco-Imperial invasion of Saxony and of the retreat of the Duke of Bevern towards Breslau (present-day Wroclaw), Prince Charles resolved to capture the strong fortress of Schweidnitz (present-day Swidnica) which contained one of the most important Prussian magazine in Silesia. He charged General Nádasdy of the capture of the fortress.


The fortress of Schweidnitz (actual Swidnica) is located in Silesia, at an important crossroad linking Breslau, Glatz, Landeshut and the axis Bunzelwitz-Striegau-Liegnitz. In the vicinities of the city, to the east of it, ran the Weistritz river with sandy banks and marshes all along its course. The Weistritz river separates Schweidnitz from its suburb of Kletachkau. To the south of the fortifications of the city lays the suburb of Schreibendt and the mill known as the Neue Mühle, on the banks of a tributary of the Weistritz: the Bögen Wasser.

The city of Schweidnitz was a fortified place which Frederick II improved from 1747 to 1756 through continuous series of works. The works were finished just for the outbreak of the Seven Years' War. Outer works were added to the walls dating from previous periods. Some of these outer works were as far as 500 m. from the city walls. The concept was new and revolutionary. It relied on defensive zones taking advantage of the lay of the land in front of the works and creating areas of cross fire. This approach was an innovation compared to Vauban's theory basing the defence on a continuous rampart completely conditioning the dispositions of the outworks. Developed by the same Frederick, this brilliant innovation, often copied in the military architecture of the XVIIIth century, allowed for a more economic use of fortifications without the huge dispersion of manpower and artillery necessary to defend the extensive perimeter of a city, and the vast construction and maintenance expenses.

The Austrians, who eventually became masters of the fortress, did not really grasp the modernity of its structures and linked the outworks with fieldworks to constitute continuous fortifications.

Map of the fortress of Schweidnitz in 1757.
Source: Kriege Friedrichs des Grossen, volume III by the German Grosser Generalstab

The role of stronghold was assumed by a kind of star or zigzag shaped fortification known as a sternschanze, consisting of a small central irregularly shaped pentagon with a three-pointed base facing the town. A small place of arms occupied the inside of this sternschanze with ramps leading to the platform protected by a parapet; a ditch separated the central redoubt from the external star-shaped curtain wall. The base of the curtain wall ran parallel to the walls of the five-pointed central redoubt whose three longer walls were parallel to those of the curtain wall and its two smaller ones ran opposite to its base. The height of the outer curtain wall allowed to fire from the central redoubt. The zigzagged outer curtain wall was fitted with a ditch and a counterscarp, a covert way and a glacis. In the inner angle between two bastions, covered caponnieres with loopholes for enfilade fire crossed the ditch to link the curtain wall to the redoubt. The central redoubt was armed with 15 heavy guns deployed evenly in three batteries placed at the extremity of each point.

Each sternschanze had its own powder magazine, barracks for its garrison and magazines providing for a certain autonomy for these isolated forts. The entrance was located at the base and accessed through a covert way. The parapet of this covert way, the caponnieres and the base of the curtain wall in the ditch were reinforced by palisades and breastworks of fallen trees. A vast network of countermine galleries existed and was later improved by the Austrians after the capture of the fortress.

Around the town of Schweidnitz there were four of these forts and other minor fortifications. Oriented to the south, the Bögen Fort (star-shaped) then, proceeding counter-clockwise, the Wasser Redoubt (an arrow shaped ravelin) oriented to the southeast, followed by the Wasser Fort in the shape of an irregular hexagon oriented to the east. To the north of this latter fort there was a ravelin (arrow shaped), then the Galgen Fort (star-shaped) which constituted the northeast angle of this ring of forts. To the northeast of it, isolated at a certain distance, there was a small arrow shaped redoubt. Oriented to the north, the Kirchen Redoubt (arrow shaped). At the northwest angle of the ring of fortifications, the Jauernicker Fort (star-shaped) reinforced by the Jauernicker Flèche (a ravelin). Then followed, oriented to the west, the Jauernicker Redoute (arrow shaped), the Garten Fort (star-shaped); the interval between the Garten Fort and the Bögen Fort was occupied by the Garten Redoubt (arrow shaped).

The Wasser Redoubt and the Wasser Fort overlooked the Weistritz river flowing to the southeast of Schweidnitz.

The Siege

Map of the siege of Schweidnitz from October 24 to November 12 1757.
Source: Kriege Friedrichs des Grossen, volume III by the German Grosser Generalstab

On October 24, Nádasdy received the needed siege artillery and was joined by Arenberg's Corps. Nádasdy was now at the head of 48 bns, 32 grenadier coys, 32 sqns and 10,000 Grenzer light troops for a total of approx. 43,000 men. Meanwhile, Prince Charles covered the approach with 60,000 men to prevent any intervention by Bevern. The Austrian army was posted in front of Bevern's Army encamped at Breslau on the opposite side of the Lohe, between Strachwitz (present-day Strachowice) and Masselwitz (present-day Maslice) with a reserve between Goldschmieden (present-day Zlotniki) and Stabelwitz (present-day Stablowice). The village of Neukirchen (unidentified location) was to its front and was surrounded by strong entrenchments.

The Fortress of Schweidnitz was garrisoned by 6,000 men under the command of Sers, governor of the place, and Grumbkow, his second in command.

On October 26 at dusk, some of Nádasdy's troops followed a sunken road from Schönbrunn (present-day Slotwina) and managed to reach a brickwork near Schweidnitz. The defenders spotted them too late and the Austrians occupied the brickwork.

On October 27, the Austrians consolidated their position around the brickwork.

In the night of October 27 to 28, the Austrians opened a zigzag trench advancing from Croischwitz (present-day Świdnica Kraszowice). They were soon within 450 paces of the glacis of the Bögen Fort. Work immediately began to erect three cannon batteries (each of 6 pieces) and two mortar batteries (each of 4 pieces). Meanwhile, men worked at the first parallel to the right of Schönbrunn and opened new zigzag trenches.

Even though Frederick II was still very busy in Saxony, he made instant arrangement for Silesia. Prince Heinrich was ordered to maintain the Saale and guard Saxony. Similarly, Marshal Keith was ordered to cross the Erzgebirge through Marienberg and Passberg with a small corps and to advance into Bohemia to draw the attention of the Austrians to that side.

In the night of October 28 to 29, while the Austrians were working at their trenches and batteries, Sers had to cancel a sortie because a large part of the troops assembled for this operation deserted, thus spoiling any chance of a surprise attack. Sers then blew up the already burned down “Neue Mühle” (New Mill) near Croischwitz to prevent the Austrians from using it as a stronghold.

In the night of October 29 to 30, Nádasdy opened a third series of trenches along the sunken road coming out of Bögendorf (present-day Witoszów). The artillery of the fortress opened a lively fire but could not prevent the junction of these new trenches with the first parallel coming out of Schönbrunn. The Austrians were even able to open the second parallel. Meanwhile work continued on the batteries in front of Croischwitz. The same night, Sers charged Colonel von Roebel of Jung-Braunschweig-Bevern Fusiliers to launch a sortie with 400 volunteers and 2 hussar sqns, followed by 300 workers, against the brickwork near Schönbrunn. The infantry attacked the parallel frontally while the hussars supported by a detachment of infantry turn the left flank by the north. The Austrian troops covering the trenches fell into disorder and the Austrian workers routed. The Prussians had enough time to flatten most of the earthworks before retiring in good order when the Austrian grenadiers advanced against them. In this action, the Prussians lost approx. 70 men while the Austrians lost 11 offices and 96 men killed or wounded and 5 officers and 250 men taken prisoners.

In the night of October 30 to 31, despite a lively artillery fire from the defenders, the Austrians were able to repair their earthworks in the area of Schönbrunn. The five batteries north of Croiswitz were completed.

On October 31 at daybreak, the five Austrian batteries opened against Schweidnitz.

In the night of October 31 to November 1, the suburb of Crosch (unidentified location) was set afire and razed by the Austrian artillery. The Austrians also began to erect batteries in the area of Schönbrunn.

In the morning of November 1, part of Schweidnitz was set afire and several buildings and a few magazines were burned down. The Bögen Fort, the Garten Fort and the Wasser Redoubt could now barely return fire. Sers evacuated the entrenched village of Kletschau (unidentified location). Indeed desertion was rapidly increasing among Grenadier Battalion Diezelsky, I./Jung-Bevern Fusiliers and Garrison Regiment Nr. 5 Mützschefahl. Grenzer light troops and grenadiers immediately occupied Kletschau.

In the evening of November 1, the fire of the batteries north of Croiswitz lessened. The Austrians worked at their second parallel, connecting it with the other trenches in the area of Croiswitz.

In the night of November 2 to 3, the Prussians managed to repair heavy damages done to the Bögen Fort. The Garten Fort, the Garten Redoubt and the Wasser Redoubt had also been seriously damaged. The Prussian guns on the walls of the fortress answered the Austrian batteries established in the area of Schönbrunn with some success. A nearly completed battery near the brickwork was almost entirely destroyed. On the other hand, the Garten Redoubt continued to suffer greatly. Sers evacuated the entrenchments of the Jauernick Flèche and of the Styrius Mill.

In the morning of November 5, the new Austrian battery near the brickwork opened against Schweidnitz to cover the erection of additional batteries. Furthermore, two new batteries had been established on the Sandberg to cover the batteries of Croischwitz. The Prussians failed to set fire to Kletschau with their artillery of the Wasser Fort.

In the night of November 5 to 6, work was completed on the batteries in the area of Schönbrunn.

From November 6, as scouts and deserters had reported that large quantities of ladders were assembled at Croischwitz and Schönbrunn, the Prussian garrison was ordered to be in combat readiness each day at 3:00 a.m.

On November 6 at daybreak, the Austrian batteries around Schönbrunn opened on Schweidnitz, adding their power to those in the area of Croischwitz. Fire broke out in the southern part of Schweidnitz. Wind pushed the blaze towards the north-western part.

In the night of November 7 to 8, the Austrians extended their second parallel from Bögendorf and established a breaching battery of twelve 24-pdr guns opposite the Bögen Gate and a second breaching battery of four pieces on the right wing of the second parallel. The Prussians for their part worked at strengthening their defensive works.

On November 8, Batthyányi Dragoons and Zweibrücken-Birkenfeld Dragoons arrived at Nádasdy's camp from the main Austrian army. They were posted in the gap between the Bavarian and Württemberger contingents. The tower of the City Hall was set afire.

From November 8, half the Prussian garrison remained in combat readiness each night. The Garten Fort had a garrison of 350 men; and the Bögen Fort, of 200 men.

Early on November 9, the two new beaching batteries opened against the walls of Schweidnitz.

On November 10, Nádasdy third parallel was finished. The Austrians had not yet gained a single outwork. That day, their breaching batteries created a three-men wide breach in the walls of Schweidnitz. In the afternoon a gable collapsed and buried 2 officers and a number of soldiers and prisoners under its debris. Daily, some 50 men of the Prussian garrison deserted. By that date, the Prussian artillery had been almost entirely silenced. At 4:00 p.m., Nádasdy summoned Sers to surrender. The latter asked for a cease-fire of a few days to allow him to refer to the Duke of Bevern. Nádasdy rejected this request and immediately reopened fire on the fortress. Impatient at making so little progress, he resolved to risk a coup-de-main and to launch a general assault against the outworks surrounding the place. Accordingly, he instructed his generals to take measure for the storming of the place. Three grenadier companies were assigned to the attack of each of the three defensive works. Two of these companies would attack the faces of each work while the third would move around it to attack their flanks. Each group of grenadiers would be supported by 1 bn. The entire operations would be supported by a reserve of 7 to 10 bns. Simultaneously, Grenzer light troops would make diversionary attacks on the Galgen Fort, on the suburb of Schreiberdorf and on the Wasser Redoubt. During these operations, 900 grenadiers and 9 bns would man the trenches.

On November 11 at dusk, all Austrian batteries opened a lively fire against Schweidnitz. Meanwhile, the troops destined for the attack took position in the trenches.

At 11:00 p.m., at a signal, the bombardment should cease and be followed by the shooting of 13 bombs against the defensive works. Some confusion then occurred and the attacks on the three targeted works were not launched simultaneously. The Garten Redoubt was the first to be attacked, shortly followed by the attack on the Bögen Fort and then by the one on the Garten Fort.

The attack against the Garten Redoubt was guided by a Prussian miner NCO who had previously deserted. The small garrison under Second Lieutenant von Garbsky of Garrison Regiment Nr. 5 Mützschefahl was surprised and surrendered after a brief combat. The Austrians immediately turned the 8 pieces of this redoubt against the town.

The garrison of the Bögen Fort was under the command of Captain von Königsegg of Kurssell Fusiliers. Most palisades of this fort had been destroyed and barriers had to be hold together with cables. There were no ingenieur-officer in the fort. The mines were not usable, three were charged, but still without fuse. The garrison of the fort drove back the first assault. However, a second attack immediately followed while the supporting battalion attacked a flank of the work. Furthermore, Banal Grenzer troops advanced from Bögen, guided by a deserter. They managed to force their way in from the left flank. The defenders were driven out of the covert way. Königsegg was finally forced to surrender.

In the Garten Fort, where Colonel von Gablentz of Kreytzen Fusiliers commanded, the garrison had enough time to prepare for the incoming assault. Three mines were timely blown up and the garrison opened fire. The first assault was then repulsed with salvoes of grapeshots from the fort and from the walls of the fortress. The defenders resisted until daybreak.

During these simultaneous attacks on three outer defensive works, no force were sent from the place, allegedly because the drawbridge of the Crosch Gate was afire and the Bögen Gate was blocked by the debris of a nearby tower who had collapsed. Another reason was the high desertion rate which did not induce Sers to use his troops at night.

On November 12 at daybreak, the Austrians were masters of the three defensive works and were prepared to defend them. The breaching batteries reopened against the walls of the town. Meanwhile, scaling ladders were brought forward for the planned attack. Sers, convinced of the uselessness of any further resistance, now beat the “Chamade”. However, bombardment continued. Nádasdy later apologized, explaining that the signal had not been heard in the batteries. Seeing that fire continued, Sers sent Captain von Hachenberg as messenger to Nádasdy. Bombardment finally ceased. The garrison was allowed to march out of Schweidnitz with the honours of war but became prisoners of war. As soon as the capitulation was signed, the Austrians occupied the Bögen Gate and the Nieder Gate.

Bombardment of Schweidnitz - Copyright: Ing. Jiří Sissak Ph.D, reproduced with the kind authorisation of the Monastery Ordo Sancti Benedicti, Broumov, Czech Republic

On November 12, a few days after his victory at Rossbach, Frederick took 13,600 men (19 bns, 28 sqns) of his own army and marched from Leipzig as fast as he could to relieve Schweidnitz.

On November 13, the Fortress of Schweidnitz was delivered to the Austrians.

On November 14, the garrison of Schweidnitz marched under escort towards Königgrätz. The Austrians threw a garrison of 3,000 men under FML Count Thürheim in Schweidnitz. This garrison immediately started to repair fortifications.

On November 18 at Grossenhain, Frederick learned that Schweidnitz had capitulated on November 12. This was a very brief resistance for such a strong fortress.


During the siege, the Prussians had lost 200 men killed or wounded, 911 deserters, 800 men sick, 180 pieces and 48 colours. The prisoners of war comprised 4 generals (von Sers, von Grumbkow, von Kreytzen and von Rebentisch), 194 officers, 48 Beamte and surgeons, and 5,971 men. The Austrians had lost approx. 3,000 men, including 1,200 men killed of wounded.

Immediately after the capitulation of Schweidnitz, Nádasdy, leaving a garrison of 3,000 men in the fortress, joined Prince Charles bringing the united Austrian army to 80,000 men. Nádasdy's corps deployed on the right wing between Bethlern and Oppenau. The Austrians could now concentrate their attention on Bevern's Corps defending Breslau.

Order of Battle

Austrian Order of Battle

Commander-in-chief: General of Cavalry Franz Leopold von Nádasdy auf Fogaras

Summary: 20,000 men

Prussian Order of Battle

Commander-in-chief: Seers

Summary: 6,000 men


This article incorporates texts from the following books which are now in the public domain:

  • Anonymous, A Complete History of the Present War, from its Commencement in 1756, to the End of the Campaign, 1760, London, 1761, pp. 223-226, 236-240
  • Archenholz, J. W., The History of the Seven Years War in Germany, translated by F. A. Catty, Francfort, 1843, p. 127
  • Carlyle T., History of Friedrich II of Prussia vol. 18
  • Donnersmarck, Victor Amadaeus Henckel von, Militaerischer Nachlass, Karl Zabeler, 1858
  • Grosser Generalstab Kriegsgeschichtliche Abteilung II: Die Kriege Friedrichs des Grossen, Part 3 Der siebenjährige Krieg 1756-1763, Vol. 4 Groß-Jägersdorf und Breslau, Berlin, 1902, pp. 181-188, Appendix 16, 17
  • Plan of the Austrian siege of Schweidnitz in 1757, published in 1761 now in a museum in Berlin (ref. no. X2322-3)
  • Tielke, J.G.: Beytrage zur Kriegs-Kunst und Heschichte des Krieges von 1756 bis 1763, Vol. 4, Freyberg, 1781


Carlo Bessolo for the description of the fortress in the "Map" section

Krzysztof Czarnecki for the orders of battle