The foundation stone of the citadel was laid on 4 November 1715 and it is generally believed that the year of completion was 1738, although other works followed in the years to come.
It is a star form fortification which was provided with seven bastions and six ravelins, crossed by vaulted galleries and all delimited by deep moats. The seven-star shape is given by the seven bastions, which form the „safety enclosure” of the most important and best-protected fortification. Built right in the heart of Transylvania, the fortified city proved to be the most imposing Baroque monument of the province.
The purpose of the citadel was that of military defence, provided by the bastion system, the type of artillery pieces it was armed with and the large number troops located inside the citadel. The citadel was attacked once but not conquered. The episode took place in 1849, when 8,000 Hungarian soldiers besieged it without success.
The Alba Carolina Citadel has seen spectacular transformations in recent years, becoming more and more visible on Europe’s tourist map. The restoration works (co-financed by European funds) have also taken into account to valorize its exceptional cultural heritage. Now the citadel is an open air stage for cultural festivals and concerts held by famous orchestra top Romanian and foreign artists.