Callixtus (218-223), the founder of the cemetery, does not lie in it. He perished in a popular outbreak, having been thrown from the windows of his house into the square, the site of which corresponds with the modern Piazza di Santa Maria in Trastevere, the _area Callisti_ of the fourth century. The Christians recovered his body, and buried it in the nearest cemetery at hand,--that of Calepodius by the Via Aurelia (between the Villa Pamfili and the Casaletto di Pio V.). Urban, his successor (A. D. 223-230), opens the series in the episcopal crypt of the Appian Way. His name, OYPBANOC E (πίσχοπος), has been read on a fragment of a marble sarcophagus. Then follow Anteros (A. D. 235-236), Fabianus (A. D. 236-251), Lucius (A. D. 252-253), and Eutychianos (A. D. 275-283),--in all, five bishops out of the eleven who are known to have been buried in the crypt. In looking at these humble graves we cannot help comparing them with the great mausolea of contemporary emperors. A war was then raging between the builders of the catacombs and the occupants of the imperial palace. It was a duel between principles and power, between moral and material strength. In 296, bishop Gaius, one of the last victims of Diocletian's persecution, was interred by the side of his predecessors in the crypt; in 313, only seventeen years later, Sylvester took possession of the Lateran Palace, which had been offered to him by Constantine. Such is the history of Rome; such are the events which the study of her ruins recalls to our memory. THE TOMB OF GREGORY THE GREAT. In the account of his life given in the "Liber Pontificalis," i. 312, two things especially attract our attention: the mission sent by him to the British Isles, and his entombment in the "Paradise" of S. Peter's. Beginning with the latter, we are told that he died on March 12 of the year 604, and that his remains were buried "in the basilica of the blessed Peter, in front of the secretarium, in one of the intercolumniations of the portico." This statement requires a few words of comment. We have seen how the bishops of the age of persecutions were buried in the underground cemeteries, with a marked preference for those of the Via Appia and the Via Salaria. From the time of Sylvester (314-335) to that of Leo the Great (440-461) they still sought the proximity of martyrs, and obeyed the rule which forbade burial within the walls of the city. Sylvester raised a modest mausoleum for himself and his successors over the Cemetery of Priscilla, on the Via Salaria, the remains of which have just been discovered.[109] Anastasius and Innocent I. found their resting-place over the Cemetery of Pontianus, on the road to Porto; Zosimus and Sixtus in the church of S. Lorenzo; Boniface I. in that of S. Felicitas, on the Via Salaria.