The next morning was a Sunday, and Saladin and his mother worshipped in the village’s small parish church. The church was dark and cramped, but its walls were brightly painted, covered with pictures based on Bible stories and the lives of the saints. Most striking was a very severe Christ, whose image stood above the chancel arch. The righteous climbed a ladder towards Him on one side of the arch, and the damned fell screaming into perdition on the other. The villagers, listening to their priest’s mysterious Latin words, smelled of their fields, of grass and earth and dung.

After the service, Thomas said he would speak to them at last of his discoveries.

XV

XV

In a cramped, smoky visitors’ room in the priory, Thomas served them mead. Saladin sipped from his cup. The flavour was disgusting, the drink a kind of fermented honey, but it delivered a strong kick.

‘Listen to the story I have to tell you,’ Thomas said. ‘Listen, believe, try to understand.’

He had come upon this truth by accident, when Thomas, in the service of Joan, was studying the progress of the Mongols.

Armed with al-Hafredi’s glimpse of the future, Joan and her ancestors had been able to profit from a foreknowledge of the Mongols’ advance. But in the year 1242 the Mongols had suddenly withdrawn from Europe. Thomas, digging into the reasons for this reversal, eventually found a man who had actually been at the court of the Mongols in that crucial season, two years ago. He was a knight called Philip of Marseilles. Devout, strong, fearless, Philip had taken the Cross more than once.

And he had agreed to serve as a legate for the Pope, in the pontiff’s hopeful negotiations with the Mongol Great Khan.

The Mongols had been a nomadic people, one of many who hunted and warred across the vast grassy ocean of the Asian steppes. The Mongols’ expansion across the world was the dream of Temujin, who called himself Genghis Khan, which meant ‘the emperor of mankind’, and he taught the Mongols to believe that they and only they were born to rule the whole world.

Genghis first unleashed his war dogs against China to the east. With one ancient civilisation reduced, the Mongols next assaulted the prosperous Islamic states to their west and south, especially Khwarazm, where they shattered an irrigation system that had endured since antiquity. Then Genghis’s son Ogodai assaulted the Viking-founded cities of Russia to the north. Mongols cared nothing for cities or civilisation; resolute nomads, they wanted only plunder, and space to graze their horses.

Then the Mongols turned west, to Europe, and Christendom.