When Roman authority withdrew, a Roman military commander called the Dux Britanniarum had used this legionary capital and the forts on the Wall to take control of the old northern province. The polity had survived well, despite raids on the east coast, where over the decades a German people known as Angles had landed in great waves. For a time the British had confined the Angles to a coastal fortress called Bebbanburh, and pushed them back still further to an offshore island called Lindisfarena. But the Angles kept coming, and had long since broken out. Now their kingdom sprawled across the north of Britain, and in just the last few years they had taken Eoforwic for themselves.

And today, cattle were herded beneath the colonnade of the principia, and German chieftains stalked over its marble floor. Ammanius, surveying all this, tried to convey to a reluctant Wuffa his sense of loss, of regret, a feeling that he had been born out of his time.

They stayed in the city only one night, before travelling on to the centre of the new Anglish kingdom on the east coast. Bebbanburh was a stronghold built on to a plug of hard black rock that loomed uncompromisingly above a bank of dunes. They had to climb stairs cut into the rock to reach its summit. The stronghold was crude, only a handful of wooden-framed huts surrounded by a hedge. Once this slab of rock had been the whole of the Angles’ holding. Now it was the heart of a kingdom that sprawled across northern Britain.

It was named after the wife of an Angle king. The British had once called it Dinguardi, but nobody cared about that.

The weary travellers were greeted by a thegn of the local king, and were granted lodging in a small, cramped hall. In this typically Germanic building Wuffa felt more at home than since he had left Coenred’s village. It was a spectacular site too, looming above a restless sea over which the comet spread its ghostly light. But the bishop was soon in a black mood, for as he pressed the king’s advisors for news of how he could track down Isolde’s prophecy he was told there was yet more travelling to be done - and this time west, along the line of the old Roman Wall itself. ‘The Last Roman’, the thegn said superstitiously, said to be a descendant of Isolde herself, was to be found haunting a Wall fort called Banna.

Wuffa, indifferent, found himself a corner to curl up on straw that smelled of cattle, and fell soundly asleep.

He was woken in the pitch dark by a heavy, wine-soaked breath, a clumsy hand fumbling beneath his blanket. Without thinking about it he raised his knee, jammed it into a fat belly, and lashed out with his fist. Ammanius fell back with a grunt; of course it was him.