Sforza Castle

Galeazzo II Visconti raised the first fortification here in the second half of the 14th century, finished around 1370 and named the Castello di Porta Giovia after the nearby gate. The Roman Castrum Portae Jovis had stood on the same ground, one of the four defensive castles of Roman Milan, serving as castra praetoria once the city became an imperial capital. Galeazzo's successors — Gian Galeazzo, Giovanni Maria and Filippo Maria — enlarged it into a square castle with sides 200 metres long, four corner towers and walls up to seven metres thick, and Filippo Maria moved the ducal court into it permanently from the palace by the Duomo. When he died without legitimate heirs in 1447 the Golden Ambrosian Republic, set up by the Milanese nobility, destroyed the castle as the seat of the lordship it had just overthrown.

The condottiere Francesco Sforza, husband of Bianca Maria Visconti, broke the republic and in 1450 began rebuilding the castle as his own residence; having no arms of his own, he kept the Visconti viper. The first stone was laid on 1 July. Five months later the two stretches of the Ghirlanda wall towards Porta Comasina and Porta Vercellina were done and the round towers of the Carmine and Santo Spirito begun — round because gunpowder had made the old square towers a poor defence. Money was short: a carriage tax on every city of the duchy came in late or not at all. Plague struck the works in the summer of 1451; that October the Torre Castellana of the Rocchetta was finished and Foschino Attendolo installed as castellan.

In 1452 the duke engaged Filarete and Jacopo da Cortona for the central tower, which still carries Filarete's name. Filarete fell out with the ducal engineers, whom he dismissed as bricklayers, and his insistence on terracotta and marble corbels slowed the work; the military architect Bartolomeo Gadio eventually took it over. After Francesco's death his son Galeazzo Maria kept the work going under Benedetto Ferrini, with Bonifacio Bembo among the painters at the ducal chapel. In 1476, during the regency of Bona of Savoy, the tower that bears her name was built.

Ludovico il Moro came to power in 1494 and made the castle the seat of his court. Leonardo da Vinci frescoed rooms of the ducal apartment with Bernardino Zenale and Bernardino Butinone, and painted the interlaced foliage of the Sala delle Asse in 1498. Nothing survives of the colossal equestrian monument to Francesco, destroyed by French soldiers before it could be finished. In the years that followed, French, Milanese and German troops fought over the castle and damaged it badly; an elongated bastion known as the tenaglia was added, perhaps to designs by Cesare Cesariano. Nine different governments held Milan in the thirty-six years after Ludovico's fall.

After the French victory at Marignano in 1515 the defeated Maximilian Sforza fell back into the castle with his Swiss mercenaries and the cardinal-bishop of Sion. Francis I followed them into Milan, his sappers laid mines under the foundations, and the defenders capitulated. In 1521 the Torre del Filarete, by then in use as an armoury, blew up; the explosion is put down to a French soldier setting off a charge by accident. Francesco II Sforza, briefly restored, repaired and enlarged the fortress and fitted part of it as a residence for his wife, Christina of Denmark.

The castle passed to Charles V in 1536, handed over by Count Massimiliano Stampa, who had held it since 1531 under oath to cede it to no one but the emperor or his successors. With the governor's seat moved to the Ducal Palace, it stopped being a princely residence and became the core of a citadel, garrisoned by between 1,000 and 3,000 men under a Spanish castellan. The frescoed halls were turned into carpenters' shops and storerooms and brick henhouses went up in the courtyards. From 1550 the defences were rebuilt in the modern manner with Vincenzo Seregni: a star fort, pentagonal at first and then hexagonal, its points later taken to twelve, with outer works three kilometres long covering some 25.9 hectares. Ditches completed in the early 17th century cut the castle off from the city altogether. When Lombardy passed from Spain to the Austrian Habsburgs it stayed a fortress.

Archduke Ferdinand left Milan on 9 May 1796, leaving 2,000 men in the castle under Lieutenant Colonel Lamy with 152 guns and good stocks of powder. They saw off an attack by pro-Jacobin Milanese, then stood a French siege from 15 May to the end of June. Napoleon first ordered the defences repaired for a garrison of 4,000, and in April 1799 they were besieged in turn by returning Austro-Russian troops; French rule returned after Marengo. A popular petition to pull the castle down as a symbol of the old tyranny had been raised in 1796, and by decree of 23 June 1800 Napoleon ordered its total demolition. From 1801 it was carried out in part on the flanking towers and completely on the Spanish bastions, to public rejoicing, and the ground behind became the parade square.

Under Austrian rule after 1815 the castle gained prisons and ditches, and during the Five Days of Milan in 1848 Radetzky ordered the city bombarded with its guns. When the Austrians pulled back the Milanese dismantled part of the defences facing the city, and after Milan became Savoyard the population sacked the castle in reprisal. Twenty years on, many in Milan wanted it demolished for a residential quarter; instead Luca Beltrami carried out a restoration close to a reconstruction, aimed at returning the building to its Sforza-era form. It ended in 1905 with the inauguration of the Torre del Filarete, rebuilt from 16th-century drawings and dedicated to King Umberto I, assassinated a few years before. The old parade ground was planted as the Parco Sempione. Allied bombing in 1943 damaged the castle severely, and the post-war rebuilding for museum use was the work of the BBPR partnership.