The Catacomb is believed to have been created by future Pope Callixtus I, then a deacon of Rome, under the direction of Pope Zephyrinus, enlarging pre-existing early Christian hypogea. Callixtus himself was entombed in the Catacomb of Calepodius on the Aurelian Way. The crypt fell into disuse and decay as the relics it contained were translated from the catacombs to the various churches of Rome; the final wave of translations from the crypt occurred under Pope Sergius II in the 9th century, primarily to San Silvestro in Capite, which unlike the Catacomb was within the Aurelian Walls.[1] The Catacomb and Crypt were rediscovered in 1854 by the pioneering Italian archaeologist Giovanni Battista de Rossi.[1]