Aaron of Lincoln

Right.

The text mentions figures like Aaron of Lincoln.

He lived in twelfth-century England and was at the time the wealthiest man in the entire country.

He wasn't huddled in a ghetto.

The boom and bust.

Right.

Because if this human capital made them so successful, so wealthy, so vital to the growth of empires, why do those same empires keep turning on them? Why does Aaron of Lincoln's wealth eventually lead to the Jews being expelled from England in 1290? How does success breed such lethal vulnerability?

This is where we transition from economics to sociology and theology.

He could be encouraged to lend and then squeezed by taxation whenever the crown needed money.

In England, Aaron of Lincoln became one of the wealthiest men in the realm, and when he died in 1186, the Crown seized his entire estate and created a special department of the treasury simply to collect his debts.

That is to say, the state often used the Jews as a proxy to lend money in a way that Christians were not allowed to.

When Edward I stopped using the local Jews to exploit his other subjects, he banned their lending in 1275, and in 1290