of Constantine) was proceeding, somewhat before A.D. 1615 the same Pope designed to make the approaches to the sacred "Confession" of the apostle at the west end of the church more dignified, and it was in the course of building stairs and making certain excavations which were necessary to carry out his plans that his architect came upon a number of graves in the immediate neighbourhood of the walls which encircled the hallowed tomb of S. Peter. Here was evidently the old Cemetery of the Vatican which originally had been planned in the first century by Anacletus. Some memoranda of this discovery were made. But it was a few years later, when more important excavations were carried on in the pontificate of Pope Urban VIII (Cardinal Barberini) in connection with the foundations necessary for the support of the enormous baldachino of bronze over the high altar, that this most ancient cemetery was more fully brought to light.
The circumstances which led to these discoveries of Urban VIII were as follows: The date is about A.D. 1626; Bernini was the architect in the Pope's confidence, and it was determined to replace the existing canopy over the altar and confession, which was considered too small and insignificant for its position, by the great and massive bronze baldachino which now covers the high altar and the confession leading to the sacred tomb.
The materials for this mighty canopy and its pillars were obtained from the portico of the Pantheon, the roof of the portico of that venerable building being stripped of its gilded bronze. This portico had survived from the days of its builder Agrippa, the son-in-law of the Emperor Augustus.
The act of Urban VIII, thus robbing one of the remaining glories of ancient Rome, was severely criticised in his day, and the well-known epigram survives to commemorate this strange act of late "vandalism": "Quod barbari non fecerunt, fecit Barberini."
The new baldachino or canopy of Bernini's was 95 feet in height, and is computed to weigh nearly 100 tons. To support this enormous weight of metal it was judged necessary to construct deep and extensive foundations. It was in the digging out and building up of these substructures
