The Citadel of Alessandria (Italian: Cittadella di Alessandria) is a star fort and citadel in the city of Alessandria, Italy. It was built in the 18th century by the Kingdom of Sardinia, and today it is one of the best preserved fortifications of that era. It is one of the few fortifications in Europe still in their original environment, since there are no buildings blocking the views of the ramparts, or a road that surrounds the ditches.
On 10 March 1821, during the Piedmont insurrection, the blue, red and black tricolour of the Carbonari was raised on the Citadel’s bastions by Colonel Ansaldi. This was the first use of a tricolour flag in the history of Italy.
The Citadel has been Italy’s tentative list of UNESCO World Heritage Sites since 2006.
The fortress lies across the river Tanaro in the north-west side of the city of Alessandria. The site is one of the lowest in the Piedmont region with an altitude of about 90 metres (300 ft) above sea-level.
Since its foundation, 1168, the town of Alessandria was always meant to be a border town with a strategic-military vocation. From the 14th century has joined the Visconti of Milan against Monferrato and Asti, with the Sforza then in the 15th century, and consequently under the Spaniards rule after, throughout the 17th century.
The construction of the fortress began immediately after the signing of the Treaty of Utrecht in 1713. The treaty handed ownership of the Citadel from the Spaniards to the House of Savoy. A massive fortification project followed, during which much of Alessandria’s town-planning were changed to bolster the fortress’s defenses.
In order to meet the needs of defense of the new state of Savoy, it was decided to build a massive fortress designed to function as a barrier of military transits traveling along the “Road of Flanders“, the ancient Spanish military road that connected the harbors of Genova, Savona and Finale Ligurewith the Netherlands.
The Citadel plan was commissioned by King Vittorio Amedeo II and effectively built, in 1732, by King Charles Emmanuel III. The project’s architect was Ignazio Bertola. The fortress is a six-star hexagon-shaped structure.
The Citadel was built entirely at the expense of the ancient quarter of Borgoglio (or Bergoglio) provoking strong urban revolution. It was completed in its main components in the forties of the 18th century while inside the fortified hexagon the buildings of the civilians were gradually demolished to make way for new military quarters and the inhabitants were forced to relocate, replaced by a garrison ever more numerous.
The result is an immense fortress which extends over 74 hectares (180 acres) whose longer side is parallel to the axis of the river. The Citadel is a perfect example of modern fortress composed of six bastioned fronts supplied with cavalieri crossed by tunnels and casemates. The fortress is surrounded by a wide moat, in connection with the Tanaro river through flooding tunnels, scheduled to be flooded by the waters of the river, and protected by tenaglioni, ravelins, counterguards and ridottes.
The entrance is by a long stone bridge that leads to a large area surrounded by multi-storey buildings arranged along the axis of the ancient quarter, all protected by resistant embankmentsconstructed between 1749 and 1831.