As patron saint and bishop (c. 432–450) of Bologna, San Petronio was credited with erecting some of his city’s most famous and enduring edifices. According to his Vita, or life story, in the fifth century Petronio traveled to the Holy Land, where, with only a reed as his tool, the saint took the measurements of the monuments commemorating Jesus’ life and death. On returning to Bologna, the Latin text records, the saint constructed a “monasterium in honore sancti Stephani” (a chapel, or monastery, in honor of Saint Stephen), modeled on the holy sites of Jerusalem. Today, this 12th-century Vita provides the first clear association of Santo Stefano with the fifth-century bishop. The Vita author believed that the building program of San Petronio must have been considerably grander and more lavish than the 12th-century complex, but that the organization and symbolism were the same.

An early-16th-century miniature (below left), by Giovanni Battista Cavalletto, depicts a miracle said to have taken place during the church construction. In the foreground, San Petronio, wearing a bishop’s miter and carrying a staff, heals a bricklayer who fell while working on the walls. Behind them stands the half-built church, rendered in careful detail (compare with the black-and-white photo, p. 28). The rotunda of Santo Sepolcro is complete. Just to the right, the Church of San Giovanni Battista lacks only its roof; its distinctive exterior pulpit has already been constructed.

The story of the building of the church is told in the earliest version of Petronio’s Vita, dating to 1162–1180 (preserved in the Passionario di Santo Stefano, codex no. 1473, in the University Library of Bologna):

“And indeed, he [San Petronio] constructed this very spacious and lofty monasterium [chapel of Santo Stefano] with different kinds of stone, surrounded by a colonnade of porphyry and other precious stones of different colors, with bases and capitals on which were sculpted figures of men, animals and birds. With great labor, he raised a monument, marvelously built according to the model (ad instar) of the Tomb of the Lord, following the arrangement he had seen, and with care guided by knowledge, he had measured carefully with a reed, when he was in Jerusalem … The walls surrounding the tomb on all sides were constructed of fitted stone, cut and squared and shining with exceeding brightness.

“There was another building there, built from its foundations with a great variety of columns surrounding an atrium in the center … In this way, he extended [the construction] to the place that symbolized (figurate) Golgotha—this is named Calvary—where the Cross was erected, on which Christ was placed for the salvation of the world … In that very place, which is called Golgotha, he erected a wooden cross, which in length and width and in every other aspect was made like the Cross of Christ …

“Indeed, on top of the mount [Bologna’s Monte Oliveti] he constructed with every care and eagerness a monasterium of John the Evangelist … In the middle of the atrium, the place is marked from which Christ ascended to heaven … In the space between Golgotha and the Mount of Olives is a valley called Josephat; in this place is the Field of Hakeldema … Another of his works is not to be overlooked. With great care, using measurements he took with a reed in Jerusalem, he made a pool, like (instar) the Pool of Siloam, where the Lord cured the man born blind.”