The amount of trade going on was astounding. The houses were built long and thin, crowding each other for frontage on the main streets. In the workshops behind these frontages tanners scraped and cobblers hammered, potters turned their wheels, and weavers treadled their looms with threads of wool weighted by pierced discs of fired clay. Leofgar the weapons dealer was on friendly terms with many of the smiths. In the houses open fronts wares of all sorts were displayed, from pottery and wooden tableware and jewellery to broiled rats sold to children for a clip from a silver coin. Outside the carpenters’ shops cups and plates were heaped up, wheel-turned from blocks of ash, dozens of them all but identical to each other, remarkable if you were used to hand-made goods. Cynewulf was very struck by one store that sold nothing but shoes, sewn from leather or moleskin, racked up on shelf after shelf like roosting birds.

Ibn Zuhr fingered a pottery jug, deep crimson, symmetrical, well finished. He ignored the Danish jabber of the man who was trying to sell it to him. ‘Look at this. I haven’t seen anything of this quality since I was taken from Iberia. And I would guess that this is the first genuine city, as a Greek or a Moor would understand it, to be functioning in Britain since the Caesars. All in a decade!’ Ibn Zuhr seemed fascinated, in his cold, supercilious way. ‘The Danes, you know, have trading links from Ireland to the Baltic, from Greenland to Iberia. Under them, trade is booming, within the country as well as beyond.’

‘The Danish trade can boom all it likes,’ growled Arngrim, ‘until Alfred comes here and lops off its head like a weed. And then we’ll get back to the old ways.’

Ibn Zuhr the slave could only agree with his master.

Leofgar led the party to the city’s heart, where the shells of many Roman buildings still stood. It was quiet here, away from the bustle of the Danish markets. Cynewulf curiously walked inside the immense walls of what Leofgar called the principia, once the headquarters of a Roman legion, a mighty structure that could still be seen for miles around. Though now its roof had collapsed, leaving heaps of smashed tiles, the principia had stood, without maintenance, for four hundred years. Leofgar said that the Emperor Constantine had been elevated to the purple in this very building, accompanied by lightning strikes, flights of birds, crosses in the sky and other miracles. Cynewulf was a natural sceptic, and found it very hard to believe that the mightiest emperor of them all could have had anything much to do with Britain - and certainly not Northumbria, this dismal corner. But Leofgar seemed to enjoy the fantasy. Now the ground was being cleared of its paving stones, and bodies planted in the exposed earth. Thus a Roman principia was being turned into a pagan cemetery.