If you’re thinking of Byzantium, then you can only think of the Hagia Sophia, and Herrin provides a reminder that it was not some late flowering of the ancient world, but the energetic burst of something new, and behind it once again was a strong woman – not (just) Justinian’s famous and much maligned empress Theodora, but a wealthy senatorial lady, Juliana Anicia, who had just built a grand church, St Polyeuktos’s, on her own property. But it was Theodora to whom more credit was due, for it was just before the great church was begun that she, ancient accounts seem to agree, stiffened Justinian’s backbone when he was about to flee before a mob riot that conveniently cleared a large tranche of the centre of Constantinople.