DEEP in the Undercroft Museum at York Minster, there’s a little clay tile that is, for me, almost as moving as the entire Minster that contains it; for, inscribed discreetly, perhaps hastily, on that tile, dating from about AD 100, is the chi-rho, the two Greek letters that stand for Christ and are the mark of a Christian.

Earlier than the earliest church, earlier than the creeds — as early, perhaps, as the Gospels themselves — here is the evidence of the good news of Christ’s resurrection reaching England, before it was England. Somebody, perhaps a slave, perhaps an adjunct or auxiliary of the Roman army’s fortifications at Eboracum, had carried the faith, even as far as this ultima Thule, this farthest-flung outpost of empire, and chosen, for a moment, to leave the mark of their faith on a clay tile before it dried.

The tall Minster that towers above that little tile bears witness to the eventual ascendancy of the Christian faith and to its persistence, and its capacity, time and again, after every defeat, to recover and rise again from the ashes, as, indeed, the Minster itself has done, seven times burned and seven times rebuilt, as I remembered in a poem addressed to the Minster in my collection The Singing Bowl (Canterbury Press, 2013):

York Minster broken bone-house, broken home
Of broken bread, in all your funeral rites
You witness Resurrection. Seven times
Your skeleton has crumbled into ash. . .
Stand up old stones, hold in your bones the light,
The dispensation to each piling year
Of Love’s abiding truth.

But the Minster itself, in all its splendour, makes a more ambiguous witness, too: a witness to the Church’s gradual accumulation of wealth and power and privilege — a development that could scarcely be imagined by the unnamed underling who dared to inscribe the sign of a proscribed religion on that clay tile in the undercroft.

And just outside the Minster is a modern statue of Constantine, who was in York when the news reached him that he had become the Emperor. Legend has it that he, too, saw inscribed the chi-rho, the sign of Christ, not on a poor clay tile, but resplendent across the heavens, and heard the words “In hoc signo vinces” (“In this sign, thou shalt conquer”). So, Constantine, not yet himself a Christian, had the eagles on his standards changed to the new symbol, and went on, through slaughter and violence at the Battle of the Milvian Bridge, to triumph and power as Emperor.

Christians can, of course, be grateful to Constantine for the freedom to worship openly which was given them in the Edict of Milan in 313, the year after that battle. But it was a tragically short step from being tolerated by the Empire to using the levers of imperial power to enforce its own intolerance. Within a couple of generations, the persecuted Church was itself a persecutor.

Perhaps Constantine misunderstood his own vision. Perhaps “In hoc signo vinces” didn’t mean swapping emblems, exchanging one logo for another. Perhaps it really meant that only through Christ, and through the way of the cross, will you conquer. Only when you love your enemies and bless those who persecute you, only when you meet your adversaries with the words “Father, forgive,” will Christ, who is Love, conquer through you.

The Church is, once again, feeling marginalised, despised, and, in places, oppressed; but it might be better for us to take as our insignium the faithful little sign in clay below the Minster’s impressive edifice rather than the statue of Constantine, at ease and in power, which stands, enticingly, beside it.