Introduction; 1. St Peter's and the city of Rome between Late Antiquity and the early Middle Ages Paolo Liverani; 2. From Constantine to Constans: the chronology of the construction of St Peter's Basilica Richard Gem; 3. Spolia in the fourth-century basilica Lex Bosman; 4. The early Christian Baptistery of St Peter's Olof Brandt; 5. The representation of Old St Peter's Basilica in the Liber Pontificalis Rosamond McKitterick; 6. The Mausoleum of Honorius: late Roman imperial Christianity and the city of Rome in the fifth century Meaghan McEvoy; 7. Popes, emperors and clergy at Old St Peter's from the fourth to the eighth century Alan Thacker; 8. The Roman liturgical year and the early liturgy of St Peter's Peter Jeffery; 9. Interactions between liturgy and politics in Old St Peter's, 670-741: John the Archcantor, Sergius I and Gregory III Éamonn Ó Carragáin; 10. A reconstruction of the Oratory of John VII (705-707) Antonella Ballardini and Paola Pogliani; 11. Old St Peter's and the Iconoclastic Controversy Charles McClendon; 12. The Veronica, the Vultus Christi, and the veneration of icons in medieval Rome Ann van Dijk; 13. The Carolingians and the Oratory of Saint Peter the Shepherd Joanna Story; 14. Plus Caesare Petrus: the Vatican Obelisk and the approach to St Peter's John Osborne; 15. The legendary of St Peter's Basilica: hagiographic traditions and innovations in the late eleventh century Carmela Vircillo Franklin; 16. The stucco crucifix of Saint Peter's reconsidered: textual sources and visual evidence for the Renaissance copy of a medieval silver crucifix Katharina Christa Schüppel; 17. St Peter's in the fifteenth century: Paul II, the archpriests and the case for continuity Carol M. Richardson; 18. Filarete's renovation of the Porta Argentea at Old St Peter's Robert Glass; 19. The altar of Saint Maurice and the invention of tradition in Saint Peter's Catherine Fletcher; Epilogue. A hybrid history: the antique basilica with a modern dome Bram Kempers; Appendix. Letter of the Canons of St Peter's to Paul V concerning the demolition of the old basilica, 1605 Carol M. Richardson and Joanna Story.