The fortress is located North-West of the city of Alessandria, from which it is separated by the river Tamaro. It is the lowest zone of the piedmont region, about 90 metres 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 XVIIIth - XXth centuries, between the Savoy state, Republic of Genoa and State of Milan.
The Citadel was built in the ex-district of Borgoglio, 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 defence 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 20 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 Borgoglio'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.
Today the Citadel of Alessandria is a state-property administered by the Ministry of Defence. It stands for a real challenge of re-use and restoration of the ancient complex. Thanks 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.
Satements of authenticity and/or integrity
From the architectural and town-planning points of view, the main characters of the fortification have been preserved because it is a state-property administered by the Ministry of Defence. Today the Military Administration and the Municipality of Alessandria are setting necessary rules to enhance and use correctly the complex, in respect of the property's protection and in order to obtain better fruition. A 'Committee for the Protection of the Citadel; has been appointed: it is made up of the Municipality, the 'Magistrate of the River Po' and the Ministry of Cultural Activities and Properties and it is presided over by the Province of Alessandria.
Comparison with other similar properties
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.