If Thalius had expected to see a soldier on that wooden throne, he was disappointed. Constantine was a big-boned, strong-looking man in his early forties, but he wore his hair down to his shoulders, so luxuriantly blond Thalius was sure it had to be false. He was dressed in a long, flowing robe of what looked like silk, embroidered with flowery designs done in gold. Even his shoes were studded with gems. And though Thalius thought he detected a soldier’s bluff amiability in Constantine’s not unhandsome face, to approach him you had to go down on your knees and press your head to the floor.

He muttered, ‘Why, he’s not like a Roman at all. He looks like something out of Egypt or Persia. Augustus would have been horrified.’

Tarcho growled, ‘He looks like what he is - the Emperor. Do you expect him to dress like a latrine cleaner? He has to put on a show. And he’s a good lad, this one.’ He cupped his hands and called out, ‘Good on you, Constantine!’

Thalius knew that Constantine had always been popular among the British troops. After all it was they who in Eburacum, on the death of his father Constantius Chlorus, had elevated thirty-five-year-old Flavius Valerius Constantinus as the new ‘Augustus’, one of the college of emperors, and then had fought under him when Constantine had achieved his greatest victory so far in dislodging a rival, Maxentius, to become sole ruler in the west.

And he had won with the help of the Christian God, Constantine declared. On the night before the decisive battle outside Rome, he had a dream that the Christian God came to him. In the morning he had his troops chalk crosses on their shields. That victory had cemented God into his life, and his empire, for good.

The fruits of Constantine’s conversion were visible before Thalius now. The Emperor’s mother Helena travelled with him; once a concubine, she was becoming a kind of pilgrim with a mission to travel across the empire to Judea in search of relics of Christ Himself. And there were bishops among the Emperor’s retinue, on the stage with him, almost as grandly dressed as he was, Thalius observed with disgust, men of wealth and power a world away from the vision of the carpenter’s Son. There were cynics who muttered that it only took a mote of dust in the eye to enable anybody to see a cross in the sky, and Constantine’s ‘conversion’ may have owed a lot to the manipulation of events by the wily bishops in his court.

And some Christians of the old school, including Thalius himself, were deeply troubled that it was a warrior deity that was being cemented into the machinery of state, not the gentler God of Christ’s own teachings.