The letter had come about because of a visit by an English scholar called Peter to his sponsor, Subh, a lady of Cordoba – and Joan's distant cousin.

It wasn't difficult for Peter to find his way through the dense heart of Cordoba. Though born in England, he had spent years in Toledo, and was used to tangled Moorish streets. But Cordoba had its own intricate beauty. As he walked, he came across little squares where the prospect would unexpectedly open up, and he found himself looking down sloping cobbled streets and under arches to silent crowds of rooftops beyond. It was May, and baskets of flowers added splashes of colour everywhere.

But the city seemed half empty. There were fewer people than flower baskets, it seemed, ragged children throwing stones into dry fountains, a firewood seller leading his donkey through deserted streets. Some of the grandest houses were abandoned, the gardens weed-strewn, the vines out of control, the ponds clogged.

He found his way to the River Guadalquivir, in whose embrace Cordoba nestled. The old bridge still stood proud, the labour of the Romans enduring centuries. From here he took his bearings. To the north-west was the Jewish quarter, to the east the Christian, and between them the Moorish quarter.

And there was the great mosque, with the cross of Christ fluttering on banners above its gates. There could not have been a clearer symbol of the Reconquest. Just six years earlier Cordoba itself had at last submitted to the armies of the Castilian king Fernando III, and the most beautiful mosque in al-Andalus had been reconsecrated as a Christian church.

Peter walked out of the centre of the city, looking for the home of Subh, the sponsor of his scholarship.

The house was well appointed in the old style, a remnant of the Moorish past. The gate was open, and he walked through an elaborate archway into a small but neat patio, where vines clung to slim pillars, and pot plants stood like soldiers around a pond where fish swam and a small fountain bubbled. Peter, in his woollen tunic and with his pack on his back, dusty from the road, felt shabby.

A woman came striding out of a doorway. A small crowd of men followed her, perhaps a dozen, mostly younger than her. They were nervous, agitated, and they chattered in dense Arabic. With his bright blond hair and blue eyes, Peter felt even more out of place.

When the woman saw Peter she stopped dead. 'Who are you?'

She was taller than Peter, and aged perhaps forty, judging from the lines that gathered around her full mouth. But her hair was as dark as her eyes, her cheeks were high and her nose strong, and there was a sway to her ample hips that was almost animal. Peter was twenty-two years old and a virgin. He was overwhelmed by her primitive force.

He bowed hastily, but in the process his pack tumbled over his shoulder and clouted him on the head. Some of the younger men sniggered. 'I am Peter,' he said nervously. 'A scholar from Toledo. We have been corresponding.'

'We've been more than just corresponding, Peter of Toledo,' she said. 'I've been paying your wages for the last year, and I've kept you alive from the look of your scrawny frame. Well, you evidently know who I am.'

'You are the lady Subh, who-'

'Oh, straighten up, man, I can't abide bowing and scraping.'

There was an amused glint in her eye that told him she knew exactly the effect she was having on him. He said, even more confused, 'I have brought the fruits of my studies into the history of your family-'

'I should hope you have or there'd be little point you coming all this way, would there? Look, young man, I'm afraid I don't have time for you just now. We have something of a family crisis going on.' She waved a hand at the men behind her. 'Look at this lot. All my relatives, nephews, cousins, even a few uncles. All flocking around me, the way they came huddling around my husband when he was alive, may he rest in the peace of Allah. I won't bother introducing you because they're not worth a clipped crown, the lot of them. All save this one, perhaps. Peter of Toledo, meet my son, Ibrahim.'

Ibrahim was about Peter's age, perhaps a bit younger. He wore a tunic and leggings of a severe black cloth. He bowed to Peter. He was handsome, but his eyes, startling blue, were cold. 'What are you, Peter of Toledo? French?'

'English.'

Ibrahim grunted, uninterested. 'All Christians are the same.' He turned away.

'Ibrahim is as strong as his father,' Subh said, 'but ten times as difficult. Follows the teaching of the Almohads. Allah be thanked for sending me such a devout son.'

'Your mockery is inappropriate,' Ibrahim said sternly.

'Yes, yes. Well, we don't have time for this. Come.' And without another word she swept out of the courtyard and into the street beyond. The relatives followed her like baby geese.

Peter stood for a heartbeat. Then he dropped his pack in a shady corner and ran after the little mob, for he had no idea what else to do.

He found himself striding alongside Ibrahim. 'Where are we going?'

'To the mosque. Zawi is in trouble with the Christians.'

'Who is Zawi?'

'A cousin. Another one of the hapless flock who huddle under my mother's wing, and look for her protection when their foolishness and impiety leads them into trouble.'

He sounded stern and contemptuous, as only a very young man can be, Peter thought, aware of his own youth. 'You don't sound as if you have much respect for your family.'

'When the Christian armies came, my cousins did not fight for Cordoba as men. Now they cluster around a woman for protection. They are less than men.'

'And,' Peter asked carefully, 'did you fight?'

'I was too young,' Ibrahim said quickly.

Which Peter, versed in interpretation, understood to mean that his formidable mother had not let him fight. 'I would be interested to learn of your culture,' he said now. 'The principles of the Almohads, who see the whole world as a unity "plunged in God". A fascinating concept.'

Ibrahim glared at him with stony contempt. 'You know nothing of our culture. No Christian does.'

'That remark only shows that you know little of Christians yourself. I am a student, and a translator. I speak and write Arabic, pure Latin, and the dialects of the Castilians and the Aragonese, as well as Greek, French, English and other tongues. In Toledo I have translated works of Arab scholars into Latin, and Latin into Arabic, and-'

'You plunder the intellectual wealth of a higher culture as you plunder our African gold.'

Peter didn't rise to that. 'You can't translate philosophy without knowing something of its context.'

'Perhaps you think we all wandered in from the desert. Moors have been in this country for five hundred years.'

'I know that,' Peter said. 'But the Almohads did come from the desert, only a few decades ago – didn't they?'

Ibrahim was predictably offended, and stalked away after his mother. Peter was forced to hurry after them, his feet already aching from his journey.