Peace of Augsburg

September 25, 1555

Charles V's brother Ferdinand brokered a religious settlement at Augsburg allowing each German prince to choose Lutheranism or Catholicism for his lands. Cuius regio, eius religio became the rule: whose realm, his religion. It held, barely, for sixty years, until the Thirty Years War tore it apart. The exclusion of Calvinists ensured the religious question was only partly resolved, storing tensions that exploded in the Thirty Years' War.