Fortress of Breslau

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Hierarchical Path: Seven Years War (Main Page) >> States >> Prussia >> Fortress of Breslau

Origin and History

In the 18th Century, Breslau (present-day Wrocław) was the political capital of Silesia and one of the key-points in its defensive system. By 1740, its large fortifications were outdated. Until 1740

Until 1740

The most important parts of the defensive works were the fortifications of the city proper which consisted of the main ramparts, surrounding the entire city, and of eleven large bastions. The oldest of these bastions was the Scheeren Bastion located at the south-east corner of the city, erected in 1544 by the architect Lorenz Gunther. Towards the end of the 16th Century, Hans Schneider von Lindau built several additional bastions: the Ziegel Bastion (1586), the Schloss Bastion (1587), the Sand Bastion (1588), the Hiob Bastion (1594), the Schweidnitzer Bastion (1598) , the Taschen Bastion (1598) and the Bernardiner Bastion (1604). All of these works were designed according to the rules of the Italian School of Fortification, with full masonry walls, gun emplacements in retired flanks and large casemates. The remaining bastions of the city fortifications were made in Old Dutch Style, by architects of the Sabisch family. Between 1643 and 1645, the Graupen Bastion was constructed; from 1667 to 1670, the Zwinger Bastion; in 1678, the Hunde Bastion; and in 1693, the Schweidnitzer Bastion, the last one. The perimeter of each bastion was protected by wide water moat. Furthermore, several gates were protected by outworks: the Ohlauer Thor, Ziegeler Thor (1639-1642) and Schweidnitzer Thor (1699) were each covered by a ravelin; a large crownwork was located in front of the Nicolai Thor (1634-37); and a small counter-guard in front of the Ziegeler Thor (1704). The covert way was one of the main weakness of the fortifications of Breslau. By 1740, only a small portion of this covert way had been completed.

There was a second group of fortifications on the islands of the Oder River. They had been built by Valentin von Sebisch after 1630. During the 17th Century, several groups of sconces (earthworks) were built on and around these islands: a sconce on the Mühl Island (1631), a sconce in Schiesswerder (1639), a bridgehead sconce protecting the bridge across the Oder (1640), a sconce on the Sand Island (1642), large entrenchments on the Burgerwerder Island (1643), a large crownwork replacing the old bridgehead sconce across the Oder (1662-64), and finally two redoubts on the Burgerwerder Island (1683).

Furthermore, Dominsel (Cathedral Island) had its own fortifications separated from the fortifications of Breslau. This island belonged to the Catholic bishop of Breslau and had been gradually fortified by Swedish, Saxon and Habsburg forces during Thirty Years' War (1618-1648).

From 1741 to 1756

After capturing Breslau, Frederick the Great initially wanted to rebuild a strong fortress, but eventually only a few defensive works were renovated.

In 1744, the extension of the covert way began. However, by 1756, only a small part of it had been completed. In 1746, a new Mathias Sconce was erected and the Hunde Bastion was renovated at the cost of 4,911 Thalers. Two years later, in 1748, another work, the Oder Bastion was renovated at the cost of 2,000 Thalers. In 1753 and 1754, a bastion of the Ohlauer Thor and the Ohlauer Ravelin were rebuilt. After 1750, about 8,000 Thalers were spent to keep the water moat, the most important part of city defensive system, in good condition. Only one additional work was built during this period: a modern casemate serving as powder magazine which was erected in 1751 at the cost of 2,974 Thalers. The last part of the defensive system was the palisades surrounding the city. By 1756, only half of the required palisades had been completed.

In the period between 1741 and 1756, only 34,000 Thalers were invested to modernize the defensive system of Breslau. In 1756, the Fortress of Breslau did not look any different than in 1741.

Fortress artillery

At the beginning of Prussian occupation of Breslau, the fortress had a large quantity of artillery pieces. In August 1741 there was a total of 303 pieces in Breslau. From this total, 154 were cannon (from 1-pdr to 64-pdr), 39 veuglaires (from 5-pdr to 10-pdr) and 77 cannon smaller than 1-pdr (probably swivel guns). There were also 19 howitzers and 4 mortars. Of these artillery pieces, 156 were planted in the defensive works while the rest were kept in two arsenals in Breslau. The heaviest artillery pieces were deployed in the largest bastion of the Fortress of Breslau: the Taschen Bastion who contained 20 pieces (1 x 15-pdr howitzer, 2 x 10-pdr veuglaires, 1 x 12-pdr gun, 1 x 10-pdr gun, 1 x 6-pdr gun, 4 x 6-pdr guns, 2 x 5-pdr guns, 3 x 3-pdr guns and 8 x quarter-pdr guns). The biggest and most impressive piece was the 12-pdr gun named “Wilde Sau” (Wild Boar). It was one of the oldest and biggest guns in Breslau, cast in 1543 by Michael Heiliger, and weighed more than 4 tons.

There are only few records about later artillery equipment of Breslau. In 1757 the fortress was defended by only 88 cannon (6 x 24-pdrs, 25 x 12-pdrs, 7 x 10-pdrs, 21 x 3-pdrs, 8 x 4-pdrs, 13 x 3-pdrs and 2 x 2-pdrs), 4 howitzers, 14 mortars and 32 smaller guns.


In 1741:

In 1745:

In 1750:

In 1755:

In 1760:

The Fortress of Breslau also had its own company of fortress artillery, established in 1742. It had 6 officers, 23 NCOs and 123 gunners.

Between 1741 and 1791, the fortress was under the command of:

  • since 1741: Lieutenant-General George Heinrich von Borck
  • from May 20 1742 to November 22 1757: Major-General Caspar Ernst von Schultze
  • from November 21 to 24 1757: Lieutenant-General Johann George von Lestwitz
  • from November 22 1757: Lieutenant-General Johann Friedrich von Katte
  • from November 22 to December 19 1757: FML Salomon Sprecher von Bernegg (during the Austrian occupation)
  • from December 24: Carl Ferdinand Baron von der Hagen (aka von Geist)
  • in 1758: Major-General Johann Christoph von Brandes
  • from May 3 1758: Major-General Johann Friedrich von Kreytzen (or Friedrich von Kreytzen)
  • in 1758 (interim) then from November 22 1761 to March 20 1791: Friedrich Bogislav von Tauentzien

Garrison infrastructure

As for to the city fortifications, the infrastructure for the garrison was weakly developed by the Prussians between 1741 and 1756. A granary, erected between 1743 and 1746 on the old city arsenal, was the only masonry work added during this period. It was a large, 8 stories high work, which could hold about 7,000 tons of cereal. The rest of the buildings were made of cheap timber. In 1749, five barracks were added on the medieval city wall. Each barrack was a small work who could house 150 soldiers. The last military building built before 1756 was the main guard house erected in 1745 and 1746 on the market square.

Events during the War

Austrian siege of 1757

Prussian Siege of 1757

Austrian Siege of 1760

Russian attack of 1761


Podruczny, Grzegorz: Twierdza Wrocław w okresie fryderycjańskim. Fortyfikacje, garnizon i działania wojenne w latach 1741-1806, Wrocław 2009

Podruczny, Grzegorz: Król i jego twierdze.Król i jego twierdze Fryderyk Wielki i pruskie fortyfikacje stałe w latach 1740-1786, Oświęcim 2013


Grzegorz Podruczny for the initial version of this article.