Visconti Castle

Galeazzo II Visconti conquered Pavia in 1359 and ruled it as the western portion of Visconti territory. He began the castle in 1360 as a residential palace for the sovereign court rather than a fortress, with military functions concentrated in the surrounding citadel, and the building was finished within about five years. Petrarch, visiting in the autumn of 1365, called it "an enormous palace in the citadel, a truly remarkable and costly structure". The architect is not identified with certainty; the work has been tentatively attributed to Bernardo da Venezia, who was active in Pavia from 1389.

Beside the castle the Visconti laid out a walled hunting park reaching the Certosa di Pavia, the Carthusian monastery Gian Galeazzo founded in 1396. Gian Galeazzo had ousted his uncle Bernabò in 1385 to become sole ruler of Milan, continued to reside at Pavia, and directed military campaigns against neighbouring powers from the castle. Its western tower held the Visconti Library, expanded under Gian Galeazzo; Geoffrey Chaucer is said to have visited it in 1378.

After Gian Galeazzo's death in 1402 the ducal capital reverted to Milan, but the castle kept being decorated: Filippo Maria Visconti had Pisanello fresco one of its rooms, and Francesco Sforza, Duke of Milan from 1450, arranged to preserve the existing paintings, calling in Bonifacio Bembo to restore the Great Hunting Hall in 1457 and again before Galeazzo Maria Sforza's marriage to Bona of Savoy in 1468. On 17 January 1491 Ludovico il Moro married Beatrice d'Este in the castle's ducal chapel. That year Ludovico also had his nephew Gian Galeazzo Sforza and his wife Isabella of Aragon moved into the castle, where they lived until 1495, the year of Gian Galeazzo Sforza's suspicious death. Louis of Orleans, a Visconti descendant who became King of France as Louis XII, invaded the duchy in 1499 and occupied Pavia; under French rule roughly half the Visconti Library was carried off to Paris.

The Duchy of Milan became a battleground of the Italian Wars. The French withdrew from Pavia after the Battle of Ravenna in 1512 and the Sforza returned, only for Francis I to conquer Milan and Pavia again at Marignano in 1515. The Battle of Pavia in 1525, fought in the Visconti park itself, ended with Francis I defeated and taken prisoner, and damaged the park's walls badly enough to start their long decline. After his release the French attacked again in the War of the League of Cognac: Odet de Foix, Viscount of Lautrec, besieged the castle in 1527, and French artillery destroyed its north-eastern side along with two towers, taking the castle's most richly decorated apartments with it. France lost the war again, and Pavia returned to the Holy Roman Empire with the Sforza reinstated as dukes. When Francesco II, the last Sforza duke, died without heirs in 1535, Charles V took direct rule of the city; Spanish builders later raised new city walls along the line of the ruined north-eastern side, cutting the castle off from its own park.

Napoleon's forces occupied Pavia in 1796 and turned the castle into a barracks, covering its roof in earth for protection against artillery, which let in damp that damaged the fabric further. Its foundry was reopened and enlarged into the artillery arsenal of the Kingdom of Italy until 1814, and the returning Austrians kept the castle as a barracks after 1815. After Italian unification in 1859–60 it passed to the Italian army, garrisoning 1,200 men and 600 horses; this prolonged military occupation was the primary cause of the deterioration of the frescoes that once decorated its rooms, which now survive only in fragments. Military use ended in 1920, and restorations completed by the 1940s adapted the castle for public use while preserving its existing form. Listed as Italian national heritage, it now houses the Pavia Civic Museums.