The Vatican City, one of the most sacred places in Christendom, attests to a great history and a formidable spiritual venture. A unique collection of artistic and architectural masterpieces lie within the boundaries of this small state. At its centre is St Peter's Basilica, with its double colonnade and a circular piazza in front and bordered by palaces and gardens. The basilica, erected over the tomb of St Peter the Apostle, is the largest religious building in the world, the fruit of the combined genius of Bramante, Raphael, Michelangelo, Bernini and Maderna.
As the site of the tomb of Saint Peter and a pilgrimage centre, the Vatican is directly and materially linked with the history of Christianity. Furthermore, it is both an ideal and an exemplary creation of the Renaissance and of Baroque art. It exerted an underlying influence on the development of art from the 16th century.
The independent state defined by the Lateran Treaty of 11 February 1929 extends its territorial sovereignty over an integral area of less than 50ha: the Vatican City. However, this tiny enclave of Rome has, within the heritage of mankind, an importance which is inversely proportional to its derisory area. Centre of Christianity since Constantine (4th century), first the occasional, and then the permanent seat of papal power, the Vatican is at once an important archaeological site of the Roman world, the pre-eminently holy city of the Catholics and one of the major cultural reference points of both Christians and non-Christians.
Its prestigious past explains the development of an architectural and artistic ensemble, of exceptional value. The churches and palaces rest on a substratum impregnated with history. Beneath the basilica of Saint Peter, reconstructed in the 16th century under the guidance of the most brilliant architects of the Renaissance, remains of the first basilica founded by Constantine still exist, as well as fragments of the circus of Caligula and Nero, and an entire Roman necropolis of the 1st century AD, where Christian sepulchres are placed side-by-side with pagans. Saint Peter's was founded as a longitudinal basilica with five aisles, with a transept, apse, and large atrium with quadriporticus. The edifice was erected in 315 over a tomb of Saint Peter. The apse area was subjected to a lengthy renovation which, entrusted by Pope Nicholas V in 1452 to Bernardo Rossellino, over the course of the following two centuries led a total revamping of the basilica's structural appearance. Julius II inaugurated a massive artistic project for the refoundation of the entire basilica, along with the decoration of the Stanze Vaticane and the Sistine Chapel and the construction of his own tomb. In 1606, finally, Carlo Maderno built the monumental facade and in 1626 the church was consecrated. Lorenzo Bernini was entrusted in 1656 for the renovation of the area in front of the basilica. He built two enormous hemicycles with Doric porticoes linked to the church through a trapezoidal plaza that frames the facade between two inclined perspectival backdrops. It represents the Church's embrace of all Christianity.
The Vatican Palace, built on a residence of Pope Symmachus (498-514), renewed during the Carolingian period and in the 12th century, is the result of a long series of construction campaigns in which, from the Middle Ages successive popes rivalled each other in their munificence. The building of Nicholas III (1272-80) was enlarged principally by Nicholas V (1447-55), Sixtus IV (1471-84) preceding the major works of Innocent VIII, Julius II and Leo X (Belvedere and Belvedere Court, San Damaso Court and Loggia of Raphael).
The history of Renaissance art and of the Baroque period merges freely with the later additions to the palace, from Paul III (1534-49) to Alexander VII (1665-67). The works of the 18th century (the foundation of the Pio-Clementino Musem by Pius VI), of the 19th century (the Antiquities Museum of Pius VII and Gregory XVI) and of the 20th century (the new Picture Gallery) fit within the tradition of papal patronage.