What was the main papal headquarters in Rome before the Vatican, and where do Popes go on vacation? Find out on this week's exploration of papal palaces in Rome.
Richard Krautheimer, Rome: Profile of a City, Princeton University Press (2000).
Raymond Davis (editor and translator), The Book of Pontiffs (Liber Pontificalis): The Ancient Biographies of the First Ninety Bishops to AD 715, Liverpool University Press (2001).
Music: "Evening Melodrama" by Kevin Macleod (www.incompetech.com)