New Christian (Spanish: cristiano nuevo; Galician: cristián novo; Portuguese: cristão-novo; Catalan: cristià nou) was a term used to refer to Iberian Jews and Muslims who converted to Roman Catholicism, and their known baptized descendants. The term was introduced by the Old Christians of Iberia who wanted to distinguish themselves from the conversos (converts). They sometimes used other derogatory terms to apply to each of the converting groups such as Moriscos for Moors and Marranos for Jews.
Throughout the Middle Ages, Jews and Muslims sometimes converted to Christianity, often as the result of physical, economic, and social pressures or coercion. In the 14th century there was increasing pressure against Jews that culminated in the riots of 1391 in Seville and other cities. These riots caused the destruction of the Jewish courts and sparked many conversions, a trend that continued through the 15th century. Unlike the other Iberian kingdoms, Portugal was not much affected by the waves of riots. There, the population of New Christians became numerous after the forced conversions of 1497.
After the expulsion of the Jewish population from Spain in 1492 and Portugal in 1497, the remaining Jewish population in Iberia became officially Christian. The New Christians were always under suspicion of apostasy.
The governments created the Spanish Inquisition in 1478 and Portuguese Inquisition in 1536 as a way of dealing with social tensions, supposedly justified by the need to fight heresy. Communities believed that many New Christians were secretly reverting to the practices of their former religion and that numerous conversos had become crypto-Jews and crypto-Muslims.
Spanish development of an ideology of cleanliness of blood or descent excluded New Christians from society, regardless of their sincerity as converts. In Portugal, Marquis of Pombal in 1772 decreed an end to the legal distinction between New Christians and Old Christians.
After conversion, New Christians adopted Christian names. Eventually, all Old Christian names were used by New Christians.