Crypto-Judaism refers to Jews who convert to Christianity to maintain outward appearances, while secretly living as Jews. The term was first used to describe the circumstances of Jews in the medieval Christian Kingdoms of Castile and Aragon and later in Portugal. Jews here were pressured to convert to Christianity as an act of self-preservation. This trend accelerated, with increasing persecution and outrages, including massacres, particularly from the 1390s. Tens of thousands of Jews were baptised, frequently in mass ceremonies. They became known as conversos, Cristianos Nuevos (New Christians) – or, derogatorily, marranos (pigs).
Names of Jewish merchants secretly living in England in the 1600s
Conversos & Crypto-Jews