The original building of the Castle of Acqui Terme, called “dei Paleologi”*, dates back, at least to the 11th century: the first written reference clearly attesting its existence – a reference where it is mentioned as “castelletto”** – in fact, dates back to 1056. The building went through, over time, ups and downs. It was, at first, the residence of the Count-bishops of Acqui who lived there until the second half of the 13th century, when violent internal conflicts among the noble families of the city put an end to their supremacy. Later, it became the stronghold of the medieval town of Acqui and the seat of the Governors of the city, then falling, starting from 1260, under the control of the Paleologi, Marquis of Monferrato, who, even if with some interruptions and in the middle of dramatic wars and family conflicts for power and succession problems, managed to keep it, along with the rule of the city, until the beginning of the 16th century. The most significant intervals during their long domination were between 1313 and 1345, when Acqui came under the power of Roberto d’Angiò and, for a shorter time, between 1431 and 1436, a period when it was occupied by the Visconti family from Milan. The long rule of the Gonzaga of Mantova can be dated between 1536 and 1706, after which the Marquis of Monferrato regained the control of the city together with the whole county as a fief, by Amedeo VIII of Savoy. Starting from 1708, however, the complex came under the direct administration of the House of Savoy: it was then gradually deprived of its original purpose to serve as a fortress and destined, from the beginning of the 19th century, to function as a prison until recently.
There is nothing more left of the original medieval core of the castle. The oldest structures, currently existing, can be dated back, in fact, not before the second half of the 15th century: this is mainly the case of the drawbridge and of a part of the surrounding walls including a defence corner tower. After several war events and sieges that occurred between the second half of the 16th century and the middle of the 18th century, it was partially destroyed by the Spanish in 1646. The main part of the structure, still existing today and currently housing the rooms of the Museum of Archaeology, is due to the new restoration, begun in 1663. The whole separate wing of the former Prisons, instead, dates back to the Napoleonic era, whereas the last works of renovation, which led to the demolition of a section of the surrounding walls, in view of the realization of the current entrance to the upper gardens of the castle, date back to the years 1860-65.
* Translator’s note “dei Paleologi”: belonging to the Paleologo family
** Translator’s note castelletto: small castle