This is a list of non-extant papal tombs, which includes tombs not included on the list of extant papal tombs. Information about these tombs is generally incomplete and uncertain.
Papal tombs have also been destroyed by other instances of fire, remodeling, and war (most recently, World War II). Others are unknown due to creative or geographically remote methods of martyrdom, or—in the case of Pope Clement I—both. Burial in churches outside the Aurelian Walls of Rome (Italian: fuori le Mura)—in the basilicas of Paul or Lorenzo—have not generally survived.
Main locations
The main locations of destroyed or lost papal tombs include:
Papal tombs in Old St. Peter's Basilica, which once numbered over 100 papal tombs, nearly all of which were destroyed during the sixteenth/seventeenth century demolition[4]
Either San Marcello on the Via Salaria (Oxford Dictionary of Popes) or San Silvestre over the Catacomb of Priscilla on the Via Salaria (Catholic Encyclopedia)[15]
Alleged to have been buried in the chapel of St. Zeno of Santa Prassade (disproved by modern research); possibly buried under the altar of the oratory of Saints Processus and Martiniano and lost when the oratory was moved in 1548 or 1605.[16]
^Frothingham, A. L., Jr. (1891). "Notes on Roman Artists of the Middle Ages. III. Two Tombs of the Popes at Viterbo by Vassallectus and Petrus Oderisi". The American Journal of Archaeology and of the History of the Fine Arts, 7(1/2): 38.