Warsaw Fortress (Polish: Twierdza Warszawa, Russian: Варшавская крепость) was a system of fortifications built in Warsaw, Poland during the 19th century when the city was part of the Russian Empire. The fortress belonged to a chain of fortresses built in Congress Poland and the region adjacent to it during this period. It was built in stages, with the first part, known as Warsaw Citadel, built the years 1832-1834, in the immediate aftermath of the November Uprising of 1830. This initial fortification was then continually improved by the addition of further forts in its vicinity, with the work finally completed in 1874. In 1879 the government of the Russian Empire decided to carry ouf a major expansion of the fortress, which would incorporate a system of large forts surrounding the whole city. 20 forts forming this new system were constructed between 1883 and 1890. There were plans to combine the Warsaw fortress with the nearby Modlin Fortress by building a chain of connecting forts, but this work was carried out only partially. The rapid progress in the power of siege artillery required the forts to be continually strengthened. In the final period of its existence the fortress consisted of 29 forts and major works, including the older forts of the original Citadel, which were reinforced by numerous smaller fieldworks.