‘But that is because Rome’s gods are so like its subjects’ gods,’ Aurelia said. ‘The Romans were farmers, as our ancestors were, Thalius. And farmers, rooted to their land, have gods of specific places. So the gods can happily coexist - each to his own scrap of land. The Jews, though, were nomads. And their god, who became Christ’s God, was a god of no-place, or perhaps of all places, an infinite god of the sky. But there is only one sky, and in such a scheme there can be only one god. Now the Romans are accepting this sole nomadic god as their own. There will be a fight to the death, Cornelius, a battle between the old farmers’ gods and the new sky god. There cannot be room for both. Now there will only be exclusivity, and intolerance.’

Cornelius pursed his lips, and Thalius saw his deep dislike of being analysed in this way by a provincial woman, however valid the points she made. ‘Well, madam, you are here too. What is your objection to Constantine?’

Aurelia was unperturbed. Thalius imagined she dealt with bullying men like Cornelius in the course of her working life all the time. ‘It’s simple. My concern isn’t for the fate of empires, still less for the immortal souls of humanity, but for Britain.’ She railed about Constantine’s excessive taxes, and repeated the rumours she had heard that Constantine had plans to move the capital of the empire permanently to the east. ‘Somewhere in Greece, it is said, or Asia Minor, or even Africa. Do you know anything about this?’

The courtier pulled his lip. ‘There are always rumours. And there are practical issues involved, not least the defeat of Licinius first. But, yes, there is such talk. Rome will always be the heart of the empire. But Rome isn’t terribly convenient as a capital: it is far from the frontier provinces, like Britain, where the energies of the empire have to be concentrated. It is overcrowded, cluttered, difficult in the summer—’

‘And,’ Aurelia said laconically, ‘it is full of potential opponents of the Emperor, from the ever-hungry mob to old families like yours, Cornelius.’

‘I won’t deny that. Here is the bald truth. The eastern provinces are far richer than the west. Isn’t it sensible to place the capital at the economic core of the empire?’

Aurelia said, ‘Only if you want the rest to wither away and die, neglected.’

‘Well - so here we are, the Christian, the pagan and the ambitious provincial, all united in believing that something must be done. But nothing is going to happen unless we manage to decode the slave child’s puzzle-tattoo - eh?’

‘There is that, yes,’ Thalius said gloomily.

Aurelia sighed and settled back on her couch. ‘I’ve been working on it and have got nowhere, I’m afraid.’