'St. Peter's - Guide to Basilica and Square'
'St. Peter's Basilica - A Virtual Tour' by Our
'The Altars and
Altarpieces of New St. Peter's' by Louise Rice, ©1997, Cambridge
Processus and Martinian were imperial soldiers who, having been assigned the task of guarding Peter in the Mamertine prison in Rome, fell under the spell of his preaching and were converted. After being baptized, the converts were in turn arrested, beaten, and finally beheaded by order of the emperor Nero. Their bodies were buried in the catacombs of St. Agatha, on the Via Aurelia, where they remained until Paschal I (817-824) removed them for safekeeping to the Vatican basilica. Transplanted to St. Peter's, the cult of Processus and Martinian flourished.
The altar of Sts. Processus and Martinian in the new basilica, like its predecessor in the old, is one of the seven privileged altars.
Over the centuries the endowment established by Paschal I had been augmented by various wealthy donors, so that by the sixteenth century it generated sufficient income to support at least two priests, who earned their living by performing masses and other services at the altar.
Valentin (the French artist) received the commission in May 1629 and completed the work in less than a year. He was paid a total of 350 scudi, which was less than Poussin but more than either Caroselli or Spadarino were paid for paintings of comparable size.
The altarpiece represents the martyrdom or, more accurately, since their martyrdom was by decapitation, the torture of Sts. Processus and Martinian. The saints are stretched out head-to-foot on a rack. One torturer turns a crank to increase the tension; another heats metal pokers in the coals; a third prepares to beat the martyrs with a rod. As though the brutality of these executioners defies pictorial expression, Valentin had hidden their faces from view, either turning them away or casting them in shadow. Several soldiers are in attendance, their presence a poignant reminder that the men on the rack were once their comrades; Processus and Martinian too were once soldiers of Caesar, but now they are soldiers of Christ. On the left, a veiled woman watches with a gentle and sorrowful expression; on the right a raised throne, a bearded man, wearing a toga suggestive of authority, clutches his right eye with one arm while pointing with the other toward a statue of Jupiter. Angels descend on clouds, bringing palms of martyrdom.
Valentin has tried to include a great many narrative elements in a relatively small field, with the result that his composition is somewhat crowded and confused.
The painting has darkened considerably over time, and the colors have changed. This we can tell by comparing the canvas in the Vatican Pinacoteca with the mosaic replica which stands over the altar in the basilica. The altar of Sts. Processus and Martinian was consecrated in 1628. Valentin's altarpiece was installed in 1630 and remained in St. Peter's for about a hundred years until, in the early eighteenth century, it was replaced by a mosaic replica.
From: 'The Mosaics
of Saint Peter's' by Frank DiFrederico