Philip II of Spain ordered his construction in 1571, following a plan for renovation and general reinforcement of the city walls. The engineer in charge of designing it was the military engineer Giacomo Palearo, who goes by the name "el Fratin", the viceroy of Navarra Vespasiano Gonzaga y Colonna also participated. They devised a defensive system in line with the theory of the Italian Renaissance which had been put into practice shortly before in the city of Antwerp, with the "citadel" carried out by Francesco Paciotto, who also helped to construct Turin. It was an enclosure in the shape of five-pointed star. All the possible angles of attack were controlled from each point of the star shaped border. Two of the points were pointed towards the interior of the city to control that area, as stated in the documents at the time, the engineer Antonelli informed Philip II in 1569. "Pamplona is now more protected than a metropolis.. It has to have a main castle, so that the memory of the natural king's governance remains … it's still necessary to secure with strength, against their wills.. The work should serve to defend against the extrinsic danger, and also intrinsic." Do not forget that the Conquest of the Kingdom of Navarre had occurred, with incidents of reconquest with the active participation of its population. According to Alicia Cámara in the work of "Muraria", the "Citadel should be understood as a way to dominate a city from which it was possible to expect a rebellion" and as the Venetian ambassador Contarini warned that "everyone in this kingdom have hatred for the Spanish and want their natural king Juan de Albret to return".