It spans through an area of 7,000 square meters and it regularly hosts modern and contemporary art works and famous collections in cooperation with notable museums and cultural institutions from across the world.

The façade of the palazzo creates a recess in Piazza del Duomo which functions as a courtyard, known as the Piazzetta Reale (literally, a "Small Royal Square").

The Gonzaga family refurbished and transformed the ducal court into a palace suitable for a governor, with expanded and newly inaugurated rooms dedicated to official functions.

At the end of the 16th century, Governor Antonio de Guzman y Zúñiga, Marquis of Ayamonte, recruited Pellegrino Tibaldi to conduct further renovation at the royal palace.

Between 1573 and 1598 he coordinated work at the royal palace which completed overhauled the pictorial decorations of the apartments' porticoes, of the private chapel and of the Church of San Gottardo.

Several major artists of the time attended to this work: Aurelio Luini, Giovanni Ambrogio Figino, Antonio Campi and naturally Pellegrino Tibaldi himself.

Reconstruction and expansion of a new ducal theater would begin only in 1717 under the patronage of Maximilian Karl, Prince of Löwenstein-Wertheim-Rochefort, the new Austrian governor of the Duchy of Milan following the War of Spanish Succession.

The theater was larger, with four tiers of boxes and a gallery in the shape of a horseshoe; on the side was a small ridottino for gambling and a shop for drinks, sweets and costumes.

The wings of the Cortile d'Onore (Honor Courtyard) were updated in a livelier style, introducing whitewashed walls and baroque window frames designed by Carlo Rinaldi.

He recruited the famous architect Francesco Croce of the Cathedral Workshop to completely refurbish the palace interiors (furniture, silverware, chinaware and chandeliers) at his personal expenses.

Piermarini was tasked with the difficult job of balancing the demands of the Archduke, who was not willing to live in the royal palace unless it was grandly renovated, and the financial limitations imposed by Vienna.

It was decided at this time that the fire-prone Court Theater was to be built elsewhere: Teatro Alla Scala was erected, to become arguably the earliest public opera house in the world.

In 1796, Napoleon Bonaparte - still a general of the French Revolutionary Army - occupied Milan and made it capital of the newly proclaimed Cisalpine Republic, following his victory in the Battle of Lodi.

When the Austro-Russians regained control of Milan in 1799, the French government quickly auctioned most of the palazzo's furnishings and allowed the rest to be looted by the general population.

After being damaged considerably, the palazzo returned to and even surpassed its former splendor in 1805, when it was eventually named "Royal Palace": Milan had become the capital of the Kingdom of Italy, ruled by Napoleon's adoptive son Eugène de Beauharnais, who was appointed viceroy and chose it to be his official residence.

As per the exterior, Eugène de Beauharnais invited Luigi Canonica to create an entire new block called "La Cavallerizza" (nowadays occupied by the city council offices).

New stables, a large riding school and a place to give equestrian public performances, together with many offices were built in the new block in austere neo-classical style.

D'Azeglio could only enjoy the palazzo for less than a year, though: following the events that led to the proclamation of the Kingdom of Italy in 1861, it became one of the Savoy monarch's royal residences, even if it was not often occupied once the capital was moved to Florence.

Even if the bombs only hit a small part of the roof, damage quickly extended across the whole structure because of a colossal fire that was not noted and quenched in time, testament to Milan's general state of disarray on that eventful night.

All wooden fixtures and furnishings went lost and the high temperature damaged even the famous stuccoes and Appiani's paintings, ruining the Hall of Caryatids beyond repair.

The Hall of Caryatids was not redecorated to bring back its former splendor but only conservatively preserved, by removing the blackening on the walls, reinforcing the structural units and cleaning the remaining paintings.

Then the neoclassical halls were restored, to bring back the vision of Giuseppe Piermarini and the splendor of the "enlightened" era, when the city had a major role in Europe.

The building plays an important role within Milanese artistic life, having hosted in recent years prestigious exhibitions including works by Claude Monet, Pablo Picasso and other internationally renowned painters and sculptors.