It is located in the town of Nowy Dwór Mazowiecki in district Modlin on the Narew river, approximately 50 kilometers north of Warsaw.

[1] The first modern fortifications in the area of today's citadel were built by the forces of the Polish Masovian troops, which established a camp here in September 1655 to defend against the Swedish invasion.

Shortly afterward Jan Pieter van Suchtelen, a Dutch military engineer in Russian service prepared a construction plan for a mighty fortress in the area, named after the nearby town of Zakroczym.

However, the project was never accomplished as in 1806 the area became part of the Duchy of Warsaw, a rump Polish state created by and allied to Napoleon Bonaparte.

The construction started almost immediately, although Chief Engineer of the French forces Gen. François de Chasseloup-Laubat decided to build the fortress on the northern bank of the river rather than on the islands.

In addition, the area was guarded by two fortified bridgeheads, one in Kazuń on the left bank of the Vistula and the other next to Nowy Dwór Mazowiecki.

In 1810 the very concept of the fort was changed and Napoleon decided to turn Modlin into a pivotal fortress in his line of fortifications and expand it significantly by adding an outer rim of defenses.

The works continued on a very fast pace as Napoleon was planning his campaign in Russia and envisioned Modlin to become the main fortress behind his lines.

Although the following year, shortly before the outbreak of the Franco-Russian War, the number of workers exceeded 20 thousands, the fortress was never fully completed.

After 1815 the fortress found itself in Congress Poland, a state which was a part of the Russian Empire, but had considerable autonomy and an army of its own.

The Modlin fortress was renamed Novogeorgievsk in 1834[3] and during the years 1832–1841 underwent a huge expansion, to host garrison troops who were tasked with preventing another Polish uprising, as well as defend Russia's western frontiers.

The most notable new work built was a fortified barracks building 2,200 m in length, which was to serve as the last line of defense for the fortress.

Polish architect Jan Jakub Gay designed the granary not only for storing food, but also as a defensible position at the bridgehead of the rivers.

In the years 1883–1888 eight modern forts were added, roughly forming a ring with 2 to 4 km distance from the central fortress.

In 1909 when General Vladimir Sukhomlinov became the War Minister for the Russian Empire, one proposal he made was to scrap the bulk of the Russian fortress system, and Novogeorgievsk was a prime example of why they should be scrapped: The outer forts were initially built at a distance of about eight kilometers from the citadel to protect it from attacking artillery; by 1900, even field guns could fire past that distance.

The intensive new construction work started in 1912 and continued almost until the German army approached the fortress in 1915 during World War I.

The fortress was now designed to serve as a center of resistance deep behind enemy lines if the Russian army were forced to retreat from Poland.

[7] To capture Novogeorgievsk, the Germans transferred General Hans Beseler who had successfully laid siege to the Belgian city of Antwerp early in the war.

General Wiktor Thommée ensconced the Army of Łódź in the fortress after failing to fight his way back to Warsaw, and his was one of the last Polish military units to capitulate.