[1] The structure was erected at the behest of the Duke of Parma and Piacenza Alessandro Farnese and entrusted to the engineers Giovanni Antonio Stirpio de' Brunelli and Genesio Bresciani with the collaboration of Smeraldo Smeraldi.

[3] Between the late 20th and early 21st centuries, the fortress, which retains its original pentagonal shape, was renovated and used as a public park, with spaces dedicated to sports and children's activities.

The Citadel thus became a symbol of Parma's renewal, surpassing in prestige the Parco Ducale built by Ottavio Farnese precisely to give it greater dignity than other cities, including Piacenza.

[5][note 3] The choice of the pentagonal shape adopted for the citadel of Parma has its roots in the long debate that took place during the 15th and 16th centuries about what was the right number of bastions to give the structure for better defensibility for strategic purposes.

[7] Sangallo's signature feature, found in the palace-fortress of Caprarola, lies in his ability to combine aesthetics and functionality, civil and military architecture.

With the passage of time, it is possible to note the improvement of military town planning in the sixteenth century, as evidenced also by the outer wall of Castel Sant'Angelo, designed by Francesco Laparelli and begun in 1562.

Consistent with what is reported in a notarial act of 1596, the design of the main gate was said to have been conceived by Simone Moschino, in line with the criteria for the construction of monumental entrances to cities or citadels in the 16th century.

The construction time of this gate was rather long: when completed, it turned out to be divided into three bays communicating through a series of rooms intended for the guard and control units; on the upper floor, meanwhile, was located the castellan's dwelling, spaced from the facade by means of a corridor leading to the observation posts.

[note 5] Prince Ranuccio, on the other hand, personally took care of the financial aspect, while Count Cosimo Tagliaferri, "doctor of laws," attended to the administrative part.

[note 6] In addition, the meddling of Alessandro Farnese's administrators caused several problems in the technical sphere as well: this led to a long series of mutual accusations between those in charge of the project, as attested in the two letters sent by the ducal secretary Pico to Duke Alessandro in which, in addition to strongly expressing the intention of wanting to equip the fortress with guards and artillery, Brunelli is basically accused.

Disagreements between Brunelli and the administrators grew as time went on, to the point that it became a recurring practice, in order to discredit his opponent, to deliberately allow him to make design mistakes.

[note 7] In this climate, it ended up that in 1592 Brunelli was sent back to Flanders on the express order of the duke, who appointed Bresciani in his place, joined by Smeraldo Smeraldi, thus stabilizing the situation.

Among Smeraldi's most important designs are: the plan of the fortress (which includes measurements of some of its elements), a survey of the outline of the Citadel and the city walls, and a section of the moats and ramparts.

Alessandro intended to entrust his household with the economic burden of building the fortress; moreover, the realization of such an ambitious project at the same time gave employment to many citizens,[note 9] and this also unintentionally contributed to limiting the riots that arose during the periods of major famine.

[19] The project, which aimed to introduce services for citizens inside the historic structure while protecting its architectural aspects threatened by vegetation, focused on the static consolidation of the ramparts and the conservative restoration of the atriums leaning against the two monumental gates.

[19] The restoration, which could count on funding of 2.2 million euros, started with the care of the gardens, which cover more than 120000 m2 between the part inside the walls and the one outside, through pruning works, planting of new trees and landscaping of the lawns.