Who were conversos in late medieval Spain?

In late medieval Spain, conversos (from the Spanish for "converted") were individuals of Jewish descent who adopted the Christian faith. While many became devout, orthodox Roman Catholics and played prominent roles in Spanish intellectual, religious, and social life, the group was highly controversial.1234

The term emerged largely following mass conversions during the anti-Jewish riots of 1391. Because many conversos retained their former occupations and social standing, they faced intense suspicion from "old Christians," who often doubted the sincerity of their conversions. This hostility was fueled by jealousy over the economic success and social mobility of many converso families, who frequently intermarried with the aristocracy.4513

The Spanish Inquisition was established in 1478 specifically to investigate and punish those suspected of "Judaizing"—secretly practicing Judaism—a practice associated with those sometimes referred to as Marranos. Despite this persecution, many conversos remained integral to the cultural achievements of Spain's "Golden Age," including figures such as Teresa of Ávila and Bartolomé de Las Casas.453