The Citadel of Alessandria a unique place in the world
The Citadel of Alessandria is located North-West of the city, from which it is separated by the river Tanaro. It is the lowest zone of the Piedmont Region, about 90 meters above sea-level; this region was named “Mesopotamia” by humanists and destined to be always a borderland. It served as a fortress in the Late Middle Ages, especially through the XVIII – XX centuries, between the Republic of Genoa, the State of Milan and the Savoy State.
The Citadel was built in the former district of Bergoglio, after the Treaty of Utrecht in 1713, when Alessandria passed from the dominion of Spain to the one of the House of Savoy. On that occasion, the fortress was entirely rebuilt to the detriment of the ancient district, causing complete town-planning revolution to Alessandria, in order to satisfy defense needs of the new Savoy state. The players of that re-construction were king Vittorio Amedeo IInd and engineer Ignazio Bertola: the property is a huge fortress that spreads over 60 hectares and is in the shape of an elliptical hexagon, whose longer side (1 : 1,235) is parallel to the axis of the river. Its hexagonal shape is due to the need of defending the long borderline. The Citadel is a perfect example of modern-type fortress and consists of six bastions called by the names of the patron saints and was surrounded by moats to be flooded by the river’s water.
The city-entry was through a long stone-bridge leading to a huge place surrounded by multi-storey buildings placed according to Bergoglio’s previous building axes, all covered by resistant vaults and built between 1749 (quarter of San Tommaso) and 1831 (warehouse of fortifications). The construction and state of conservation of Napoleonic buildings are unique. During the French occupation,the location and effectiveness of modern fortifications made the Citadel one of the most spectacular fortresses of the empire and the richest arsenal in Europe.
After the Restoration, the re-establishment of the ancient boundaries of the Savoy state gave again a pivotal role to the Citadel. Because of the war between the Savoy state and Austria, updates were carried out to the citadel, like the ditches (1857) that make Alessandria a highly-fortified city. The victorious resistance of the Citadel during the Second War of Independence (1859) is a key-episode of the Italian Renaissance.
Thank to its strict relationship with the river and the city, it is a unique complex by itself because it was projected to defend the whole state.
Since the XVIth century military treaties have been very rich in description of hexagonal fortresses; actually, the Citadel of Alessandria is the most important one. Today, the World Heritage List does not include any similar example, except for Suomenlinna (Finland), which dates back to the same period but is completely different from the historic and geographical points of view.