Antonio Sangallo and the Construction of the Papal Grottoes

Tomb of Pius XI in the Vatican Grottoes
beneath Saint Peter's Basilica

I gave short shrift yesterday to Antonio Sangallo the younger in my eagerness to get to Michelangleo’s role in the design and construction of St. Peter’s Basilica.  I had mentioned how he had diverted materials and labor from the Basilica to build a palace for himself on the Via Giulia, Rome’s most fashionable street but his time as Capomaestro or chief architect was marked by nepotism and graft as he gave contracts to all his relatives and friends, hiring members of his clique for all the chief positions.  Yet he did make several important contributions to the project,  Despite a mutual loathing between Bramante and the Sangallo clan, he had been hired by Bramante as chief carpenter.  Bramante had recognized the young Sangallo’s genius and Antonio had not disappointed him, devising a unique system of scaffolding to brace Bramante’s massive piers until the concrete set.  When Leo X put Sangallo in charge after Raphael’s death, Sangallo constructed a scale model of the projected Basilica according to his design.  It was perfect in detail and even on a scale of 1:29 it was over twenty feet high in the dome and 23 feet long from front to back.  It cost over 6000 ducats—a parish church could have been built for less.  But it gave—for the first time—a detailed plan of what the finished Church might look like.  In the end, Michelangelo’s revisions and Maderno’s façade would (thankfully) give a very different look to the Basilica but at least now there was a plan even if it would be changed.  Just seeing a model of the Basilica made people think that it might become a reality out of the rubble pile that currently stood on the site. 

      Sangallo made an even more important contribution to the Basilica by raising the level of the floor 12 ½ feet above the level of Constantine’s basilica.  While this altered Bramante’s proportions, and not for the better, it also created the crypt beneath the nave that would become the grottoes of the papal tombs.  (In the 20^th century, the crypt floor would be lowered a meter to give more headroom.)  Despite his elaborate plans, however, actual construction on the basilica would progress little by the time of Sangallo’s death in 1546.  It was just as well as his successor, Michelangelo, wanted to clear the deck and start over.  Michelangelo would develop what his predecessors, especially Bramante, had built but at the same time he would take those elements and integrate them into a design uniquely his own.