St. Peter—keeper of the keys
The painting shows the moment when Christ, standing in the center dressed purple and blue garments, gives the keys of the heavenly kingdom to the kneeling St. Peter. This episode comes from the Gospel of Matthew (16:18-19) as Christ said to Peter: “And I tell you that you are Peter (Petros), and on this rock (petra) I will build my church… I will give you the keys to the kingdom of heaven….” The pair of gold and silver keys became Saint Peter’s attribute (an attribute, in this sense, is an object associated with a saint that aids the viewer in identifying the saint). More about Peter
The Renaissance ideal
The figures
Perugino pulled out every pictorial device in his painter’s arsenal to construct an image that is reflective of Renaissance ideals: figures, balance, harmony, and three-dimensional space. To begin with, see that the pictorial field has been clearly delineated into three distinct planes: foreground, middle-ground and background. In the foreground, on either side of Christ and St. Peter—are the other eleven Apostles. Who are the Apostles?
In the middle-ground, the figures are much smaller than those in the foreground, suggestive of their spatial distance. Not merely passersby, these figures are part of two additional stories from the life of Christ. On the left is the Tribute Money from the Gospel of Matthew (17:24-27) where the Roman tax collector demands Christ pay the Emperor’s tax. (This scene was famously represented by Masaccio in the Brancacci Chapel in Florence. On the right is the Stoning of Christ from the Gospel of John (8:48-59). The addition of these two scenes creates a pictorial device known as a continuous narrative, where two or more related events are shown occurring simultaneously in one composition.
The space
The background is comprised of three architectural structures at the edge of the open piazza (plaza), with an ideal landscape extending far into the distance behind. In order to create such a believable sense of three-dimensional space, Perugino utilized two types of perspective.
The first, one-point linear perspective, creates a believable three-dimensional space using a system of orthogonals (diagonal lines seen on the pavement—in red in the diagram above) that recede into space, converging at one point known as the “vanishing point” (which in this case is in the doorway of the central building).”
The vanishing point is located along a horizontal line, the “horizon line,” which establishes the boundary between land and sky (the blue line in the diagram above). Notice how all of the figures maintain a proportional relationship to each other as they recede into this space.
The second type of perspective Perugino used is atmospheric perspective, which is literally the effect of the atmosphere on objects observed in the distance, causing them to diminish in appearance through a bluish-gray haze, as seen in the mountains in this case.
The influence of classical antiquity
Contrapposto
One of the defining characteristics of the Italian Renaissance was the interest in all aspects of classical antiquity (ancient Greece and Rome), especially its art and architecture. That interest in manifested in Perugino’s fresco in two different ways. One is his use of contrapposto (Italian meaning “counter-pose”) for some of the foreground figures.
This pose (seen in the figure above) was known in the Renaissance through copies of the ancient Greek sculpture, the Doryphoros (above right). When standing in contrapposto, one leg bears all of the person’s weight while remains relaxed at the knee, producing a very natural stance (notice how often you stand in contrapposto every day!).
Architecture
And at either side of the piazza are representations of the Arch of Constantine (in Rome). The arch commemorates Constantine the Great, the Roman emperor who legalized Christianity in 314. Famously converting to Christianity on his deathbed in 336, he effectively became the first Christian Roman emperor. Moreover, Constantine founded St. Peter’s Basilica, the site of Peter’s burial and the location of Perugino’s fresco. Thus, the inclusion of the Arch of Constantine was an important reference to the history of Rome, and St. Peter and the basilica.