Pope John X
Twelve additional papal tombs were constructed in the archbasilica starting in the 10th century, but were destroyed during the two fires that ravaged it in 1308 and 1361. The remains of these charred tombs were gathered and reburied in a polyandrion. The popes whose tombs were destroyed are: Pope John X (914–928), Pope Agapetus II (946–955), Pope John XII (955–964), Pope Paschal II (1099–1118), Pope Callixtus II (1119–1124), Pope Honorius II (1124–1130), Pope Celestine II (1143–1144), Pope Lucius II (1144–1145), Pope Anastasius IV (1153–1154), Pope Clement III (1187–1191), Pope Celestine III (1191–1198), and Pope Innocent V (1276). Popes who reigned during this period, whose tombs are unknown, and who may have been buried in the archbasilica include Pope John XVII (1003), Pope John XVIII (1003–1009), and Pope Alexander II (1061–1073). Pope John X was the first pope buried within the walls of Rome, and was granted a prominent burial due to rumors that he was murdered by Theodora during a historical period known as the "saeculum obscurum". Cardinals Vincenzo Santucci and Carlo Colonna are also buried in the archbasilica.