Protestantism

A term used from 1529 onwards to designate “those who protested” against the practices and beliefs of the Roman Catholic Church. Prior to this date, “protestors” referred to themselves as “evangelicals”.
1529 is the year of the Diet of Speyer (or Spire), an imperial assembly of the Holy Roman Empire in the city of Speyer, held to adopted measures to halt the spread of the Reformation in Germany.