Isabella I of Castile

The decree of 31 March 1492 gave the Jews of Spain four months to choose: baptism or exile. Estimates of the number who left run from forty to two hundred thousand; no one has an exact figure, and none may be printed as settled. From that day begins the Sephardi world of the Ottoman empire, Italy, Holland and the Maghreb—that is, half of all subsequent Jewish history.

The Inquisition, established in 1478, was aimed not at Jews—over whom it had no authority—but at the conversos, the baptized, suspected of keeping the law in secret. The distinction matters and is constantly confused.