Two centuries ago, when the first crusading knights had set out to win back the Holy Land from the Saracens, they’d been successful. They’d taken Antioch. Then Jerusalem itself.

But it had hardly been a year before the crusading cause had degenerated. A huge, motley army of adventurers and looters had swept across Europe in their wake. Finding the Jewish communities in the Rhineland and on the River Danube, they’d robbed and slaughtered them.

Christian kings, and even the Church, had been appalled.

But in the decades that followed, another process had slowly begun, and the mood of Christendom had changed. For the huge, unwieldy Moslem empire had not crumbled. It had fought back. And so the long series of Crusades had begun. Some were successful—in Spain, the Moslem Moors were being pushed back. But other Crusades had been disasters.

Churchmen were puzzled. Why hadn’t God given them victory? Crusaders were frustrated. Everyone looked for scapegoats. And what better scapegoat than the Jewish community, which contained the moneylenders to whom kings, knights and merchants alike owed so much money? Soon, Jews were being accused of all kinds of crimes: even that they sacrificed Christian children.

In Paris, the Jewish community had occupied a quarter near the royal palace in the middle of the Seine, with a fine synagogue across the water on the Right Bank. In 1182, King Philip Augustus had turned their synagogue into the church of La Madeleine, and for several years the Jews had even had to leave his kingdom. With his city wall to build, and a crusading army to finance, he’d soon recalled them. The Jews of Paris had mostly lived near the northern city wall after that, grudgingly tolerated.

It hadn’t been until the reign of Philip’s grandson that the next attack had come. But when it did, it was cunning and insidious.

A Franciscan friar in Brittany named Nicolas Donin claimed that the Talmud not only denied the divinity of Jesus, but also the virginity of his mother, Mary. Soon the pope himself told every Christian king to burn the Talmud. Most of Europe’s monarchs took no notice.

But pious King Louis IX of France did. The saintly monarch who brought the Crown of Thorns to Paris, built the Sainte-Chapelle and encouraged the dreaded Inquisition was not going to fail in his Christian duty. He burned every copy of the Talmud he could find, and made French Jews wear a red badge of shame.

Jacob’s grandfather had worn the badge of shame. Yet even so, like most of the Jewish community in Paris, he hadn’t wanted to leave. And Jacob could see why.

Paris was still one of the greatest cities in Europe, far larger than London. It was an intellectual center. It had a huge trade.