Worst are the shambles, where butchers bleed their animals and leave offal to rot in the streets. Here is a pile of rotting cows’ hooves.

Another Watch guards the fortified Boulogne Gate, but this afternoon they are more interested in throwing stones at a man hanging in a basket suspended from the castle walls.

‘Get on with it!’ one of them shouts as he launches a half-brick over the moat.

‘Cut the rope, you dozy bastard,’ another bellows. ‘Then we can all go home.’

‘What’s he doing up there?’ Dafydd asks.

‘Don’t you worry about him,’ the soldier laughs.

The moat’s waters are turbid with all kinds of rubbish, and rats compete with seabirds for scraps. Two soldiers are stationed in a boat below the man in the basket though whether they are there to drown him when he falls or pull him out it is impossible to tell.

Beyond the gate sprawls a vast village of rain-damp canvas shelters in a broad sea of pale mud that stretches as far as the eye can see. The roads are raised on dykes over drainage ditches and the water in the canals reflects the dull skies above. It reminds Thomas of the marshes around the priory, and he feels a leaden depression settle on him.

‘Welcome to the parish of St Anne’s,’ Walter spits. ‘What we call the Scunnage.’

Wordlessly they follow the cart up an avenue between the tents. Some are grander than others, with standards hung from long lances thrust into the mud, and within them it is possible to see chunky sheepskin beds where the better class of captain sleep. From other tents bored men stare at them. They are not precisely friendly, not precisely hostile, and there is nowhere for anyone to sit.

Everywhere is crowded with rough-looking women and boys acting as porters, carrying jugs of ale and water, armfuls of pimps and faggots for the cooking fires. The boys are filthy and malnourished, and more than one is missing an ear. Beyond are more women, eyeing them with weary speculation. Walter waves to them, all false jocularity.

‘Whores,’ he mutters.

They move on.

‘I always hate this bit,’ Geoffrey mutters. ‘Looking for the best place to set up and everyone looking at you like you’ve got the pox.’

‘And you always end up exactly where everybody’s been shitting since a month back,’ Walter adds.

They move on through the camp until they come to its edges. Sure enough a shallow scoop has been gouged in the earth and the stench of human waste is almost unbearable. Chickens and geese and pigs are everywhere.

Then there is a priest on a grey donkey.