‘Ironically it was an assignment by the vizier himself that set me on this course . . .’

After the fitnah the taifas, coalescing and competing, had struggled to develop scholarship as a way of achieving dominance over each other; there had even been something of a renaissance as the monopolistic power of a corrupt caliphate collapsed. Seville was not to fall behind. Ibn Tufayl had the backing of his emir, and the funds to progress scholarly projects.

‘Among other things, Ibn Tufayl decided he wanted a new history of al-Andalus to be written, from the day three centuries past when Tariq led his armies of Arabs and Berbers across the strait, up to the present. It would be the first significant survey for more than a century, since the time of one Ahmad ar-Razi.’

‘And he commissioned you to do that.’

‘It was part of the condition of his funding my work on the Engines of God. I think it amused Ibn Tufayl to have a Christian working on a history of the greatest enemy of Christendom itself. But I was happy enough to take the job, as it was an excuse for me to burrow into the mountain of scholarship the Muslims accumulated over the centuries of the caliphate. Knowledge, Orm, knowledge, the greatest power of all. You never know where it might lead! And so the vizier and I came to a mutually satisfactory arrangement.

‘The work went smoothly enough. But I soon became aware of a great mystery.’

‘What mystery?’

‘Why it is that I was born a Christian and not a Muslim,’ Sihtric said. ‘Why I grew up, in England, speaking English. Why Christianity survives at all.’

XX

XX

The great expansion of Islam had begun within a generation of the death of Muhammad. It became necessary, for the first caliphs, like Roman generals, quickly came to depend on plunder to survive. ‘It was conquer or perish,’ Sihtric said. So the armies of Damascus exploded out of Arabia, swept west across North Africa, and stormed across the Pillars of Hercules and through the Gothic kingdom of Spain.

And, with al-Andalus under the control of governors appointed by the Damascus caliphate, the raiding armies went further north still. The Muslim armies crossed the Pyrenees to attack Septimania, a Gothic domain within Gaul. They were Arabs and Berbers, men of the east and of Africa, now pouring into the green belly of Gaul.

Soon, under an able general called Abd al-Rahman, all the cities of the Mediterranean coast of Gaul were in Muslim hands. It was the eighth century, less than a decade since the first crossing of the strait.