This fresco, painted by Raphael's pupil Giovanni Francesco Penni after designs by the master, depicts the baptism of Constantine, an event from the life of the emperor that is known only in legend. Although Constantine promoted Christianity and professed his faith, he is not known to have been officially baptized. The baptism depicted here takes place in the baptistry of the Lateran Basilica, which Constantine erected after his battle with Maxentius on the demolished campsite of his opponent's elite cavalry. Penni depicted the octagonal structure with its mighty Ionic pillars with great fidelity. At the center of the picture, Constantine kneels before Pope Sylvester I, who pours water over the emperor's head from a dish. Above stands a man dressed in blue holding a long cross that points to the sign of victory sent by God and is the symbol of Constantine's rule. The pope has been given the facial features of Clement VII, under whose pontificate the Sala di Costantino was painted. In addition to various clergy, a number of figures are depicted in Renaissance dress, among them, on the far left, a bearded courtier in a luxurious black-and-gray coat who points to the baptism scene.