You can now see the second episode of BBC Four’s series A History of the Eternal City, with historian and author Simon Sebag Montefiore.
This time we learn how religion has affected the Eternal City and how Christianity gradually took hold over the old pagan gods, including the martyrdom of St Peter in what is now Piazza San Pietro – alias the Vatican, which started life as Constantine’s Basilica before it was rebuilt in the Renaissance.

It was the Emperor Nero who sacrificed Peter after the Great Fire of Rome – seeking a scapegoat to blame for the fire, Nero pointed the imperial finger at the Christians.
Later, Emperor Diocletian launched his own bloody persecution of the Christians, an act which went badly wrong when they came to be seen as martyrs.
The episode also contains footage of the preserved body of a martyr, Saint Vittoria – so shut your eyes if you’re squeamish.

It was Emperor Constantine who eventually took Christianity to heart, after seeing a vision before going into battle with his rival Maxentius. He won the battle and from then on gradually replaced the ancient Roman gods with one Christian god. The Arch of Constantine was built near the Colosseum to mark his victory – but the decorations on it still contain a pagan surprise.

Eventually Pope Gregory the Great spread the Christian word from Rome, including to the Anglo Saxons in England.
Perhaps the most moving footage is of pilgrims to Rome on their knees, climbing the staircase Christ would have walked down following his sentence to be crucified.
The second episode of A History of the Eternal City is available to view at BBC iPlayer.
Buon viaggio!