The remains of Gregory the Great have also been moved several times. His tombstone must have been worn by the feet of pilgrims, as only eighteen letters out of many hundred have been preserved to our time. These were discovered not many years ago, in a dark corner of the Grotte Vaticane. Two centuries after his death, his successor, Gregory IV. (827-844), carried his remains inside the church, to an oratory near the new sacristy, covered the tomb with panels of silver, and the back wall with golden mosaics. The body remained in this second place until the pontificate of Enea Silvio Piccolomini, Pius II. (1458-1464), who, having built a chapel to S. Andrew the apostle, removed Gregory's coffin to the new altar. The coffin is described as a _conca ægyptiaca_, an ancient bathing-basin, of porphyry, which was protected by an iron grating. The chapel, the altar, and the tomb were again sacrificed to the renovation of the church in the time of Paul V. On December 28, 1605, the porphyry urn was opened, and the body of the great man transferred to a cypress case; on the eighth day of the following January a procession, headed by the college of cardinals and the aristocracy, accompanied the remains to their fourth and last resting-place, the Cappella Clementina, built by Clement VIII., near the entrance to the modern sacristy. There are now two inscriptions: one on the marble lid, "Here lies Saint Gregory the Great, first of his name, doctor of the church;" the other on the cypress case, "Evangelista Pallotta, cardinal of S. Lorenzo in Lucina, dean of this church, collected in this case the remains of Gregory the Great, and removed them from the altar of S. Andrew to this new chapel. Done by order of Paul V., in the first year of his pontificate, on Sunday, January 8, A. D. 1606." The altarpiece was not painted by Muziano, as stated in old guidebooks, but by Andrea Sacchi. The picture was removed to Paris, with many other masterpieces, at the time of Napoleon I.; but Canova obtained its restitution in 1815. It is now preserved in the Vatican Gallery; the copy in mosaic is the joint work of Alessandro Cocchi and Francesco Castellini.