Grudziądz Fortress or Fort Grudziądz is a system of forts, mainly from the 19th century, located in the area of Grudziądz and surrounding villages in northern Poland.
Its central point is the Citadel, known by Germans as Courbière's Fortress () – a stronghold in the northern part of the city, the construction of which began on 6 June 1776, on the order of King Frederick the Great of Prussia. Other forts were built at the turn of the 19th and 20th centuries. The purpose of the fortress was to defend Grudziądz and the strategic bridge over the Vistula river in case of Russian attacks.
Most of the fortifications were only used in 1806, 1807, and 1945. Many of them, including the Citadel, have been preserved to this day in good condition. Fragments of the fortifications are accessible to visitors.
Location and construction of the Citadel After the First Partition of Poland, Grudziądz fell within the borders of Prussia. There arose the need to secure the lower Vistula to protect the communication lines between Gdańsk Pomerania and Prussian lands on the right bank of the Vistula, especially since the fortresses in Gdańsk and Toruń were not yet in Prussian hands. The fortress was built on a vast plateau 1.5 km north of the city center, at the highest point of the Vistula escarpment (68.1 m above sea level, 60 meters above the level of the Vistula). It is surrounded on the north and east by the Osa river, and on the south by the . Paul von Gontzenbach, who had previously worked on the construction of the fortress in Srebrna Góra in Silesia, is considered the designer, with the construction project personally corrected by King Frederick II.
Construction began on 6 June 1776, commemorated by a stone on the bergfried, and work progressed rapidly at the beginning of August. Von Gontzenbach had a sufficient supply of building materials and, most importantly, well-trained craftsmen and laborers at his disposal. Miners were brought in for digging underground tunnels. In June 1776, there were 6,918 people working on the fortress construction (besides carters), including 367 masons. The construction was supposed to last four years, but the fortress was not yet ready by 1782 due to several reasons. In 1780, there was a shortage of bricks. At that time, old Teutonic castles in Rogóźno and Grudziądz were dismantled for the needs of the fortress, and the foundations of both sides of Bastion I were built with stone. The constantly growing demand for bricks (11 million were used for the fortress construction, with a total of 608,400 m³ of masonry work) could only be met by the fortress's own brickworks. Therefore, the brickworks located south of the fortress were expanded, and 180 bricklayers were brought in, mostly from Prussia. In 1821, the brickworks were further enlarged, and new kilns were installed, but by the mid-19th century, it was already inactive. There were also technical difficulties in setting up terraces and ramps on the Vistula escarpment – numerous springs and streams flowing from the mountain made the work challenging. Additionally, some buildings had to be founded deeper than originally planned. According to von Gontzenbach's estimate, the construction of the fortress was to cost about 1,800,000 thalers. However, this estimate quickly proved unrealistic, even though construction of some of the previously planned anti-mine tunnels, designed to destroy siege works, was abandoned. Of the planned length of 56,400 meters, only 1,246 meters of tunnels were realized, and demolition mines were also laid under the bastion ramparts and ravelins, which were used to blow up their own fortifications if they were occupied by the enemy. The construction of the fortress was completed in 1789, with the final cost of its construction amounting to 3,671,146 thalers.
The period of the Napoleonic wars The appearance of a patrol of Napoleon's army in Dragacz on 15 November 1806 caused panic in Grudziądz. Frederick William III and his wife hastily left the city, heading northeast.
Wilhelm René de l'Homme de Courbière, the governor of Grudziądz, was preparing to defend the fortress. At the beginning of the campaign, he had a garrison consisting of two battalions and two companies. By the end of 1806, the Prussian forces were augmented by three infantry battalions and one squadron of hussars, and additionally, the Citadel had strong artillery (154 cannons, 35 howitzers, and 16 mortars). In total, General Courbière had a garrison of 5,808 soldiers under his command, but it was not a homogeneous force – a significant portion consisted of Poles, Lithuanians, Ruthenians, and even Scots; this ethnic diversity caused significant problems for the Citadel's command.
The first encounter with the French forces took place on 4 December 1806, in Mniszek, after which there were no contacts with the enemy for a month.
Siege of 1807
At the beginning of January 1807, a unit of Polish insurgents led by Major Dominik Dziewanowski appeared on the left bank of the Vistula. They camped in Dragacz and began patrolling the Vistula's bank, but did not engage in any aggressive actions against the Prussians. In mid-January, the Hessian-Darmstadt Brigade arrived near Grudziądz and almost immediately launched an assault on the city. The Prussian forces defended only the northern edge of Grudziądz with a unit of 400 men and two cannons. The Prussians quickly ceased resistance and withdrew towards the Citadel, occupying field fortifications located nearby.
At the end of January, a company of infantry under the command of Captain Jan Barankiewicz appeared near Grudziądz, occupying Wielki Lubień. This unit served as a cover for the Polish forces under General Jan Henryk Dąbrowski. The appearance of Polish troops caused trouble for the Citadel's command, as Polish soldiers from the garrison began to desert. Sources mention the desertion of a non-commissioned officer and eight soldiers.
After Russia entered the war and achieved temporary successes in East Prussia, the forces of the Grande Armée withdrew from the conquered territory. Although they returned near Grudziądz the next day, the city remained in the hands of the Prussians.
The desertions from the Prussian units were exacerbated by the arrival of the Polish 11th Infantry Regiment in Wielki Lubień, commanded by Colonel Józef Wasilewski with a force of 1,600 men. Soon, other Polish units began to gather in the vicinity of the city. Preparations for the assault slowly began. Supported by Hessian battalions, the Poles captured Grudziądz on February 11. However, the attempt to capture the Citadel itself failed. After February 12, the under General Józef Zajączek arrived near Grudziądz. This marked the beginning of the proper blockade of the fortress. One battalion from the 2nd Polish Infantry Regiment of the Duchy of Warsaw and the first battalion from the participated in the blockade.
The besieging forces were still too weak and practically devoid of artillery, so a direct assault was not feasible. They limited themselves to sporadic artillery duels. During one of these duels, the city itself suffered damage, including possibly the on Castle Hill.
Even before the arrival of spring in 1807, epidemics began to break out among the combatants. Over 700 defenders died as a result. As for the attackers, there is no data available. It is only known that from the end of April to mid-May, about 200 soldiers were lost from the Polish units due to various reasons. At least some of them died as a result of the epidemics.
After the fall of Gdańsk, siege artillery was brought to Grudziądz, and intense preparations for the assault began. A rampart was started to be constructed from the northeast side of the Citadel, where cannons were to be placed. On June 27, the construction of another, closer rampart began. Three days later, just before the commencement of the general assault, a ceasefire was declared. The siege was halted upon news of the armistice following the Battle of Friedland (June 14), due to negotiations preparing for the Treaties of Tilsit. Under the Treaties of Tilsit, the areas of Grudziądz north of the Trynka Canal remained in Prussian hands. Grudziądz was one of the few Prussian fortresses that were not captured by the Napoleonic army.
After the Congress of Vienna
After the Napoleonic Wars, the Prussians did not undertake significant expansion works on the fortifications. Over time, the condition of the structures tended to degrade, especially in terms of defensive capabilities (some lunettes and certain ravelins were eliminated). The Citadel mainly served as barracks and warehouses, as well as a prison for political prisoners and a place of internment for Polish troops after the November Uprising, including Colonel Edmund Callier.
On 30 April 1862, a mutiny of Prussian soldiers of Polish nationality broke out under the command of Gotfryd Klatt, but it did not lead to significant consequences. In December 1870, Colonel , a French prisoner of war, escaped from the citadel.
By government decision in 1872, the fortress was officially abolished. The fortification structures were used, among other things, for testing new types of cannons and ammunition. However, the function of the fortress was reinstated twice for the city: after the construction of a bridge over the Vistula river between 1876 and 1888, and on 1 September 1944, due to the approach of the Red Army.
In Grudziądz, there was the headquarters of the 35th Division of the German Empire (which was transferred to Toruń in 1912), as well as: Headquarters of the 35th Cavalry Brigade () 4th Mounted Rifles Regiment () Headquarters of the 35th Field Artillery Brigade () 71st Field Artillery Regiment Groß-Komtur () Landwehr Inspection Graudenz
Interwar period In 1919, Józef Wrycza, also known as the "priest general" (although officially holding the rank of podpolkovnik in the Polish Armed Forces), sentenced to death, was imprisoned here by the Germans.
On 23 January 1920, the fortress, along with the city, came under Polish control. In the first months after regaining independence, there was a proposal to demolish the Citadel, with the intention to employ the unemployed for the task, but it was never implemented.
From 1920 to 1939, the fortress continued to be used for military purposes, despite the development of military technology and the emergence of, among other things, airplanes. Within the walls of the Grudziądz Citadel, the 18th Pomeranian Uhlan Regiment and the 16th Field Artillery Regiment were stationed, renamed in 1931 to the . There were also military warehouses (the so-called Intendance Material Depot). Some buildings were used for the needs of the .
The administration, maintenance, and modernization of the fortress facilities were the responsibility of the Grudziądz Fortification Office. The last head of the fortifications was Major Engineer Karol Wiliński.
World War II