Macson snorted his contempt of all things German.

Fearful of wyrd or not, the Germans had a vision of their own, as Belisarius learned when they came upon Offa’s Dyke. This was an earthwork wall, four or five times a man’s height, topped by a wooden palisade or in places by stone breastwork. Some of its towers and gates were manned by tough-looking warriors in mail coats, and signal beacons flickered.

And this wall was a hundred Roman miles long, a mighty fortification that ran from the estuary of the Sabrina in the south to the coast in the north, terminating at a settlement of the wealisc called Prestatyn - although there were stretches, Macson said, where it incorporated a river and older fortifications. The Dyke was a north-south barrier erected at the orders of Offa to separate his German kingdoms from the lands of the wealisc, the expelled Britons, to the west, and thereby to stabilise a troublesome border. Only a few years old, the Dyke was fresh and raw, a wound slashed through the flesh of the green British countryside.

After some days on the road, the old man, Caradwc, seemed to brighten. Belisarius wondered if the clean air away from the muddy German towns was doing him good. He began to make conversation in passable Latin. He asked about holy sites Belisarius had visited, relics he had seen in the course of his travels. ‘And tell me, when will the Emperor return to this province and sort out these heathen Germans?’

Long after the fall of the empire in the west, the emperors had nursed ambitions to regain the lost western provinces. Roman trading ships, bringing goods with which to court the British leaders, had been dispatched as part of a long-term strategy to woo back Britannia. But time had passed. New barbarian states sprouted in the ruins of the old western empire, which became an increasingly distant memory. And in the east the empire was battered by new pressures, notably a new enemy: the Saracens, the warriors of the new religion of Islam.

‘When I was a young man the emperor was Constantine the Fifth,’ Belisarius said. ‘What a warrior! He scored victories against the Saracens and the Bulgars alike. My own father served with him. It was a golden age. In the end Constantine was succeeded by a sixth Constantine, then a boy of ten, who is run as a puppet by his mother the regent. Even now people gather at the tomb of Constantine, I mean the fifth, calling on him to return and lead us. But we will never see his like again ...’

‘But,’ Caradwc pressed, gripping his arm, ‘do the emperors not still dream of Britain?’

Belisarius gently extracted his arm, disturbed by Caradwc’s anachronistic longing. ‘I’m afraid most of us don’t even know where Britain is, old man.’

Caradwc seemed unreasonably disappointed by his answer.