Calvinism was not allowed Preventing_or_letting until the Peace of Westphalia .

Instead , it gave Giving legitimacy to only two forms of religion within the Empire , Roman Catholicism and Lutheranism , leaving GiveUp out other Reformed forms of Christianity , such as Calvinism , and radical systems such as Anabaptism .

The measure was contested Competition in 1583 , when the Archbishop-Elector of Cologne , Gebhard Truchsess von Waldburg , converted Change to Protestantism , specifically to Calvinism .