The present existence of this palace is principally due to Nicholas the Fifth, the builder pope, whose gigantic scheme would startle a modern architect. His plan was to build the Church of Saint Peter's as a starting point, and then to construct one vast central 'habitat' for the papal administration, covering the whole of what is called the Borgo, from the Castle of Sant' Angelo to the cathedral. In ancient times a portico, or covered way supported on columns, led from the bridge to the church, and it was probably from this real structure that Nicholas began his imaginary one, only a small part of which was ever completed. That small portion alone comprises the basilica and the Vatican Palace, which together form by far the greatest continuous mass of buildings in the world. The Colosseum is 195 yards long by 156 broad, including the thickness of the walls. Saint Peter's Church alone is 205 yards long and 156 broad, so that the whole Colosseum would easily stand upon the ground-plan of the church, while the Vatican Palace is more than half as long again.
Nicholas the Fifth died in 1455, and the oldest parts of the present Vatican Palace are not older than his reign. They are generally known as Torre Borgia, from having been inhabited by Alexander the Sixth, who died of poison in the third of the rooms now occupied by the library, counting from the library side. The windows of these rooms look upon the large square court of the Belvedere, and that part of the palace is not visible from without.
Portions of the substructure of the earlier building were no doubt utilized by Nicholas, and the secret gallery which connects the Vatican with the mausoleum of Hadrian is generally attributed to Pope John the Twenty-third, who died in 1417; but on the whole it may be said that the Vatican Palace is originally a building of the period of the Renascence, to which all successive popes have made additions.
The ordinary tourist first sees the Vatican from the square as he approaches from the bridge of Sant' Angelo. But his attention is from the first drawn to the front of the church, and he but vaguely realizes that a lofty, unsymmetrical building rises on his right. He pauses, perhaps, and looks in that direction as he ascends the long, low steps of the basilica, and wonders in what part of the palace the Pope's apartments may be, while the itinerant vender of photographs shakes yards of poor little views out of their gaudy red bindings, very much as Leporello unrolls the list of Don Giovanni's conquests. If the picture peddler sees that the stranger glances at the Vatican, he forthwith points out the corner windows of the second story and informs his victim that 'Sua Santità' inhabits those rooms, and promptly offers photographs of any other interior part of the Vatican but that. The tourist looks up curiously, and finally gets rid of the fellow by buying what he does not want, with the charitable intention of giving it to some dear but tiresome relative at home. And ever afterward, perhaps, he associates with his first impression of the Vatican the eager, cunning, scapegrace features of the man who sold him the photographs.