The Apostolic Palace, also called the Papal Palace, is located next to the St. Peter's Basilica in Vatican city. It is an official seat and a papal residence in the Holy See.
The palace is partially visible from the St. Peter's Square. It is actually the whole complex of buildings, such as Papal Apartments, offices, chapels, the Museum and the Library of the Vatican. It is said that it has more than 1000 rooms.
The Palace was build through ages, it was changed and rebuild by order of different popes, but the first one to begin the process was Eugene III, who was a pope in the beginning of the 12th century. During his pontificate the construction of the palace began. The new building was adjacent to the St. Peter's Basilica. Nonetheless, the works were repeatedly interrupted because of the warfare led within the Vatican. It was not until the end of the 13th century when Nicholas III initiated the construction of the palace in the site where it stands today, whereas structures built earlier were assigned for the Curie. In that period, a secret tunnel, the Passetto di Borgo, which connected the Vatican with the Saint Angel's Castle, was dug. The Walls of Leon were strengthened and the project of the prospective Vatican Gardens was introduced.
The Lateran was a papal seat since the 4th century, but the buildings burnt down in fire. Because of that, after the papal court returned to Rome from Perugia in 1377, the Vatican was chosen as a new papal residence. Till the 15th century, the palace had a form of a defensive fortification. During the pontificate of Nicholas V a construction works started. The aim was to convert a papal mansion into a renaissance residence which could adequately represent dignitaries living there. It is possible to assume, that the construction of the palace we can see nowadays began in 1447. By order of the next pope, Sixtus IV, a construction of the Sistine Chapel started. Buildings creating the whole complex were added one by one till the middle of the 17th century. Over two centuries those largest renaissance European palaces were erected. The works were done by the greatest artists, painters, sculptors and architects of those times. It is worth mentioning, that even though during the centuries different elements were added, keeping integrity and the classical beauty of the complex was always a prerogative.