What is the historical background for this remark?
I assume the author is referencing the medieval persecution of Jews, although there is much myth about this.
The Spanish Inquisition, for instance, didn't really get going till the early modern era, and had no legal jurisdiction over Jews as such. Of course, the many Jews who had been forcibly "converted" but continued to practice aspects of the Jewish faith were considered by the SI to be Christian heretics, not Jews, and were thus fair game.
Nero