On 19th May 1521, Pamplona capitulates to an attack by a French contingent of 12,000 men, also backed up by Agramont troops. However, the Castle of Santiago continues to resist, with the Castilian army of Emperor Charles V inside. The French position their artillery inside the city and attack the castle from it Mayor Herrera, inside the castle, does not hesitate to open fire on the population, wreaking havoc. Ignatius of Loyola, gentleman of the Duke of Nájera, is seriously wounded in his right leg while helping to defend the castle. The French will go on to demonstrate their overwhelming superiority in terms of artillery by breaching its walls, which results in the capitulation of the Castilian army. Pamplona’s defences, especially the castle, are seriously damaged.
When war broke out in 1542 (Italian War 1542-1546) the Emperor entrusts the Duke of Alba with the reconstruction of several fortresses, among them that of Pamplona. He is accompanied by the much-respected engineer, Luis Pizaño, an eminent figure in the construction of Spanish fortifications. The following improvements are made as a result of his visit: the number of bastions is increased and casemates are added to them in order to house more pieces of artillery, the old medieval towers are demolished, embrasures are opened and parapets are built. The walls are made sloping and thicker, gateways are closed and any obstacles or dominant points that could put the fortification in jeopardy are demolished, such as the tower of San Nicolás, which was knocked down around this time. The price for its demolition amounted to the cost of a set of full regalia in crimson velvet.
Despite the improvements, the engineer Juan Bautista Antonelli issues a very negative report in 1569 about the defensive possibilities of Pamplona. A “very major castle” needs to be built.
In accordance with Antonelli’s report, Philip II entrusts the most respected engineer of the time with the design – Jacobo Palear Fratín. In 1571, the layout of the new Renaissance castle is ready: the Citadel. Work would last more than 30 years.
Spain 1532. Pizarro conquers Peru. 1534. St. Ignatius of Loyola founds “The Society of Jesus” (the Jesuits) in Paris.
Europe 1557. France. Battle of Saint-Quentin: Philip II conquers the city bearing the same name following a 17-day siege.