the ancient world is in Egypt. Mons Porphyrites was quarried to supply the rare and expensive imperial porphyry for the emperor's building works and statuary, for which it was exclusively set aside. Mons Porphyrites is in the Thebaid, which was a centre of Christian erimiticism in Late Antiquity. Emperor Diocletian did indeed commission the extensive use of porphyry in his many building projects. Diocletian also visited the Thebaid during his reign, though he was more usually associated with the Balkans, which might explain why the story's location was transposed to Pannonia over time. Joint veneration When the names of the first group were learned, it was decreed that they should be commemorated with the second group. The bodies of the first group were interred by St. Sebastian and Pope Melchiades (Miltiades) at the fourth milestone on the Via Labicana, in a sandpit where there rested the remains of other executed Christians. It is unclear where the names of the second group actually come from. The tradition states that Melchiades asked that the saints be commemorated as Claudius, Nicostratus, Simpronian, and Castorius. These same names actually are identical to names shared by converts of Polycarp the priest, in the legend of St. Sebastian. According to the Catholic Encyclopedia, however, "this report has no historic foundation. It is merely a tentative explanation of the name Quatuor Coronati, a name given to a group of really authenticated martyrs who were buried and venerated in the Catacomb of Saints Marcellinus and Pietro, the real origin of which, however, is not known. They were classed with the five martyrs of Pannonia in a purely external relationship." The bodies of the martyrs are kept in four ancient sarcophagi in the crypt of Santi Marcellino e Pietro. According to a lapid dated 1123, the head of one of the four martyrs is buried in Santa Maria in Cosmedin. Confusion and conclusions The rather confusing story of the four crowned martyrs was well known in Renaissance Florence, principally as told in the thirteenth-century Golden Legend by Jacopo da Voragine. It appears that the original four martyrs were beaten to death by order of Emperor Diocletian (r. AD 284–305). Their story became conflated with that of a group of five stonecarvers, also martyred by Diocletian for refusing to carve the image of a pagan god. Due to their profession as sculptors, the five early Christian martyrs were an obvious