Poznań Fortress
The first set of fortifications was a tight defensive ring around central Poznań, including the main citadel called Fort Winiary (now the Cytadela park).
Later, beginning in 1876, an outer defensive ring was built around the perimeter of the city, consisting chiefly of a series of "forts", which mostly still survive.
The term Festung Posen was also used by the Nazi German occupiers during the Red Army's advance in the closing phases of the Second World War, to refer to Poznań's status as one of the "strongholds" (Festungen) which were to be defended at all costs.
[1] The city lay on the shortest route from the border with Congress Poland (and hence with the Russian Empire) to Berlin, and was also an important point on the route from West Prussia to Silesia; therefore, according to General Karl von Grolman, its fortification would show that Prussia had no intention of giving up those lands, and would defeat the "continuous intrigues and plotting" on the part of the Poles.
[2] A preliminary plan sketched by Grolman on 9 July 1817 provided for fortification of Winiary Hill north of the city, as well as the area of St. Kazimierz's Church in Śródka to the east.
[3] Building was planned to begin in 1817, but initially no funds were available for the work (due to the costs of fortifying Cologne and Koblenz).
[3] In 1827, Johann von Brese, then working in the War Ministry's engineering section, was instructed to prepare a detailed plan.
The result, dated 23 March 1828, included the large fort on Winiary Hill, fortifications on the cathedral island (Ostrów Tumski) and the right bank, and the core defensive line surrounding the left-bank city.
The king gave his final approval on 14 August 1828, ordering Hake to begin construction with the Winiary fort and the weirs on the Warta and on the Wierzbak (Wierzbach) stream.
[4] On 14 March 1828 Captain Moritz von Prittwitz und Gaffron, who had been a member of Rauch's committee, was appointed chief of construction of Festung Posen.
In May, he and five subordinate officers began marking out the outline of the first fortifications – the defensive barracks of the Winiary fort (later the reduit).
Later Bastions IV, VI, II and I were constructed, and in 1860–1861 connecting roads were built, as well as a number of brick blockhouses.
[10] Later alterations to the central ring of fortifications mainly resulted from the introduction of new types of armaments and ammunition, and the building of railway and tram lines.
[13] Following work by the Landes-Verteidigungs-Kommission and a report from Field Marshal von Moltke concerning the Franco-Prussian War, King Wilhelm issued a decree on 5 November 1871 ordering the commission to prepare plans for necessary changes to fortifications in the united Germany.
The final plans were approved 24 February 1876, providing for 9 main forts (designed by Hans Alexis von Biehler) and 3 intermediate ones.
An act of the Reichstag of 30 May 1873 allocated over 7 million thalers for the project (the fifth largest amount granted for fort modernization).
Large shooting ranges were built at Komandoria and Główna in the north-east of the city, and two training grounds at Górczyn and Karolin.
Work then began with the forts on the Berlin road, to make up for the weakening of the inner ring caused by the new railway station.
Over a few years the intermediate forts Ia, IIa, IIIa, Va, VIIa and VIIIa were built, completed in 1896 according to official records.
The work required an increase in the size of the Poznań garrison, which led to the building of a barracks complex in the area of today's Bukowska and Grunwaldzka streets.
With rising political tensions, a decree of 15 May 1913 ordered the construction of new forts to create a wider ring, but this never occurred.
Even before the official decision some demolition work had begun, including the replacement of Cemetery Gate by a blockhouse by the new railway in 1889–1894.
Under the next mayor, Ernst Wilms, in 1903 a Royal Commission was set up to oversee the development of the city, under Joseph Stübben.
Names of elements of the fortifications were changed or replaced with existing Polish equivalents, while the outer forts returned to their numbering as pre-1902.
Rocha and Reduta Reformatów, aiming to leave only the stone foundations of the slopes, prepared for possible re-use.
The outer forts were generally left unchanged (apart from the undoing of certain work carried out during the war) and continued to form the basis for the city's defence plans.
In the late 1920s and early 1930s the city negotiated with the military to have building restrictions around the outer forts lifted, which was done, although a proposal to transfer the forts to the city for civil defence, and move the military line of defence further out (as the Germans had previously planned), was rejected.
In the later part of the war Poznań was declared one of the stronghold cities (Festungen) which the Nazis intended to defend at all costs, and so the name Festung Posen was revived.
