A distinctive structure in Milan, Italy, the Galleria Vittorio Emanuele II is made up of two parallel glass-vaulted arcades that cross each other to form an octagon. It is situated between Piazza della Scala and Piazza del Duomo on the latter's north side. The gallery, which bears Vittorio Emanuele II's name, was originally created in 1861 and constructed by Giuseppe Mengoni between 1865 and 1877. He was the first king of a united Italy.

In the 13th century, Bonvesin de la Riva documented in his Wonders of Milan the presence of roughly sixty porticoes in the city, which were then referred to as "covered." Porticoes, as they are known now, have been present in Milan since the city was a medieval settlement. The porticoes gradually disappeared after the arrival of the Sforza family and then the Spanish dominance; among those that did remain was the "coperto dei Figini," which ironically was destroyed to make way for the Galleria Vittorio Emanuele II. In contrast, Milan was the first city in Italy and the Austrian Empire to have a passageway in the style of what was happening in the major European capitals where passages with iron and glass roofs were being built for commercial purposes, such as the Galerie Vivienne in Paris and the Burlington Arcade in London. This passageway was part of the Galleria De Cristoforis. The De Cristoforis arcade, however, was an outlier and Milan's lone arcade for thirty years. As a result, Milan presented itself to Italy's unification without the legacy of arcades and covered passages that is more typical of towns like Turin and Bologna.

The argument over redeveloping the space in front of Milan Cathedral, which was then smaller and irregular and considered by many to be unworthy of the city's cathedral, was one of the many that had long enlivened the city and was advocated in 1839 by Carlo Cattaneo. The area's road network was similarly complicated and winding, built on ancient medieval streets that became more and more difficult to maneuver as the city's population and traffic increased. The idea to name this new street after King Vittorio Emanuele II was inspired in part by the enthusiasm for Austria's reclaimed independence, but it was also an attempt by the municipal council to make it simpler to obtain the permits for the expropriation of the apartment buildings required for the work, which were later granted by royal decree. However, the project's original municipal standards called for a straightforward arcaded walkway rather than a covered tunnel. The three royal decrees that the municipal council had been waiting for were signed in 1959–1960: one for the expropriation of the buildings to be demolished, another for the demolition of the coperto dei Figini and the Rebecchino, apartment buildings that had previously occupied what is now Piazza Duomo and were to be demolished to give the square a more regal appearance, and a final decree to authorize a lottery in order to raise the funds required for

After obtaining the permits for the expropriations, the Milan Municipality announced a competition on April 3, 1860, for the building of the new street, whose proposals were to be evaluated by a specially appointed commission. Despite the controversy brought on by the Municipality's lack of publicity for the competition, a sizable number of projects were submitted to the first competition. Of these, 176 were chosen by the commission and displayed at the Pinacoteca di Brera. The commission did not choose the competition's winner, but instead revised its guidelines for the project's forms and came up with the initial concept of a covered passageway before announcing the launch of a new competition in February 1861. In the second project, 18 projects made it to the evaluation stage, but once more there was no clear winner. However, four awards were given to the projects deemed to be the most deserving: the works of architects Davide Pirovano and Paolo Urbani, both of whom were criticized for being unsuitable for the area around the cathedral, were mentioned for their use of Andrea Palladio-inspired architecture and their eclectic designs that combined Lombard and Venetian forms. The designs of Gaetano Martignoni, who suggested a gallery in the shape of a Greek cross to link the two squares, and finally Giuseppe Mengoni, who first suggested a street modelled after the municipal palaces of the 14th century, were more appealing, albeit ultimately unsuccessful.

As a result, the third and final competition was held in 1863. Only eight projects were evaluated, three of which were submitted at the commission's invitation and five of which were submitted on a whim. Giuseppe Mengoni was declared the winner, subject to his agreement to revise some of the project. Mengoni originally intended to build a single gallery, but he later changed his mind and decided to build a cross-shaped gallery instead. A number of minor stylistic adjustments also contributed to the final forms. The concept also called for the construction of two structures that were never completed: a royal loggia in front of the entrance to the gallery and a porticoed palace facing the Piazza del Duomo. The palace in front of the cathedral was to be known as Palazzo della Independenza, continuing the Risorgimento motif of the Gallery. When construction began in 1876, it had not yet been abandoned, and as a result, the palace's foundation had already been laid. It wouldn't be archived with the loggia of the Palazzo Reale until Mengoni's passing.

On March 7, 1865, King Vittorio Emanuele II ceremoniously laid the first stone in the presence of numerous dignitaries, including the Mayor of Milan Antonio Beretta, the Italian Prime Minister Alfonso La Marmora, and diplomats from various nations after the building contract had been given to the English City of Milan Improvements Company Limited. The construction was finished in less than three years, with the exception of the triumphal entrance arch, and the Gallery was then formally opened by the king. But things did not go as planned, and in 1869 the contractor went bankrupt, forcing the town to purchase the Gallery for 7.6 million lire at the time. The entry arch and northern porticoes of the Piazza Duomo were built in 1878, although the full completion of the construction wasn't until then. However, Giuseppe Mengoni, who apparently committed suicide, was unable to witness the official opening of the finished Gallery since he fell from scaffolding while doing an inspection.

Within a few years of its first opening, the Galleria gained the moniker "Milan's salon," becoming the hub of the city's affluent social scene, which delighted in visiting the chic new stores but especially the restaurants and cafés: among the businesses founded at the time and still in operation are the Caffè Camparino, the Caffè Savini, and the Caffè Biffi. The Galleria was also at the forefront of technological advancements at the time, and in its early years, it was lit by gas. To light the lamps in the octagon, an automatic device called a "rattn" ("little mouse" in Milanese) locomotive was used, and watching the automatic lighting procedure had almost become a ritual. Even though the Caffè Gnocchi had already been employing this, for the time being, novel sort of lighting for three years, this practice was repeated until 1883, when the lighting in the Galleria was converted to electricity.

The Galleria solidified its position as the center of Milanese social life and the music scene at the start of the 20th century. During the same years, Tommaso Marinetti's disciples, who would later inspire Futurism, started gathering at the gallery. The covered tunnel transformed into a political arena of conflict between interventionists and neutralists with the start of World War I, and it was unavoidably the site of the post-war protests that gave rise to the Italian Combat Fascists. The Galleria and the rest of the city were both destroyed by Allied air raids after Italy entered World War II.

The Burlington Arcade in London, which served as the model for large, glazed shopping arcades like the Galeries Royales Saint-Hubert in Brussels (opened in 1847), the 'Passage' in St. Petersburg (opened in 1848), the Galleria Umberto I in Naples (opened in 1890), and the Galleria in Budapest, cover the street with glass arches and a cast-iron roof.

The octagonal middle area is covered by a glass dome. The Galleria di Milano, which was the forerunner of the contemporary glass-enclosed shopping center, is bigger than its predecessors and is regarded as a significant development in that regard. It is also to blame for the word "gallery" being used in reference to shopping malls. The Eiffel Tower in Paris was likewise influenced by the utilization of the iron construction.

The Galleria is frequently referred to as "the living room of Milan" or "el salotto di Milano" due to the number of stores it houses and its significance as a gathering place for eating, shopping, and shopping.

The four-story gallery, which has been open for more than 130 years, has beautiful stores with everything from haute couture and jewelry to books and art, in addition to restaurants, cafés, and bars. The ultra-luxury Town House Galleria hotel, which provides the most exclusive (and most expensive) accommodations and services in the city, is directly attached to the Victor Emmanuel II Gallery. Some of Milan's oldest businesses are housed in the Galleria, including the venerable Café Biffi, which was established in 1867 by Paolo Biffi, His Majesty's pastry chef, and was the city's first establishment to use electricity (in 1882). The Galleria also houses the upscale Savini restaurant, the Bernasconi silverware store, and the modernist Zucca bar.