In Lisbon, a crowd began a massacre of Jews who had been forced to convert to Christianity.

The Lisbon massacre started on Sunday, 19 April 1506 in Lisbon when a crowd of churchgoers attacked and killed several people in the congregation whom they suspected were Jews. The violence escalated into a city-wide, antisemitic riot that killed between 500 and 4,000 "New Christians" (Cristãos-Novos), the name for Jews who had been forcibly converted to Christianity.

New Christian was a socio-religious designation and legal distinction referring to the population of former Jewish and Muslim converts to Christianity in the Spanish and Portuguese empires, and their respective colonies in the New World. The term was used from the 15th century onwards primarily to describe the descendants of the Sephardic Jews and Moors that were baptized into the Catholic Church following the Alhambra Decree of 1492. The Alhambra Decree, also known as the Edict of Expulsion, was an anti-Jewish law made by the Catholic Monarchs upon the Reconquista of the Iberian Peninsula. It required Jews to convert to Roman Catholicism or be expelled from Spain. Most of the history of the "New Christians" refers to the Jewish converts, who were generally known as Conversos, while the Muslim converts were called Moriscos.