The Palaces of the Vatican are an agglomeration of several buildings built in different periods, starting from the time when, on their return from periods spent at Avignon (1309-1377), the Popes decided to move their offices from the Lateran building, where they had resided since the early centuries of Christianity, to the Vatican. At the onset of the 15th-century, Pope Alexander V (Alessandro V) ordered the building of the “passetto”, a walkway connecting the Castel Sant'Angelo with the Palace of the Vatican.

The Palaces began to assume their present appearance during the papacy of Nicholas V (Niccolò V) (1447-55). Sixtus IV (1471-84) commissioned the building of the Sistine Chapel, and Innocence VIII (1484-92) moved his residence to a palace he had built especially for himself on the hill of Belvedere. With the election of Alexander VI (1492-1503), the popes returned to their residence in the palace occupied by Nicholas V, which was reinforced with the construction of the Borgia Tower. During the papacy of Julius II (1503-1513), Bramante built the Belvedere Courtyard, connecting the villa of Innocence VIII with the Palaces of the Vatican. The splendid and spectacular courtyard is built on three levels and terminates in a magnificent exhedra (which Pirro Ligorio made into the famous large niche in 1560). Bramante also built the loggias of the Saint Damasus Courtyard, which were completed and frescoed by Raphael. Following the disastrous sacking of Rome (1527), during the pontificate of Paul III (1534-50), the Vatican complex was expanded with the building, as designed by Antonio da Sangallo, the Younger, of the Royal Hall (Sala Regia), the Ducal Hall (Sala Ducale) and the Pauline Chapel (Cappella Paolina) (frescoed by Michelangelo). During the pontificate of Sixtus V (1585-90), Domenico Fontana built a new papal residence (the present one) and did away with Bramante’s Belvedere Courtyard, by erecting the building that houses the Library’s Sistine Stateroom. In the 17th-century, the complex was enlarged by the construction of the Pauline Rooms, the Library and the Archive, and Bernini added the Royal Staircase (Scala Regia) and renovated the Ducal Hall (Sala Ducale). Between the latter half of the 18th- and the early 19th-century, work began to systematically set up the vast art and archaeological collections of the popes.

History of the Museum’s Setting Up
Though a first collection of antique statues had already been arranged in the Belvedere Courtyard at the time of Pope Julius II, the opening of an actual museum was conceived only at the time of Pope Clement XIII’s papacy (1758-69), and it was by his will that the Secular Museum (Museo Profano) was set up with the help of Winckelmann. The Pius-Clementine Museum (Museo Pio Clementino) was founded right after this time, during the papacies of Clement XIV (1769-74) and Pius VI (1775-99), followed by the Chiaramonti Museum, which was set up by Canova between 1807 and 1810. The New Wing (Braccio Nuovo) was opened in 1822, the Gregorian Etruscan Museum in 1837, the Gregorian Egyptian Museum in 1839, the Lateran Secular Museum (now called the Gregorian Secular Museum) in 1844, followed by the Pius Christian Museum (both established in the basilica of Saint John Lateran, and only later transferred to the Vatican). The Missionary Museum of Ethnology, the Historical Museum and the Modern Art Collection were set up in the early decades of the 20th-century. And lastly came the Picture Gallery, opened to the public in 1932.