This principle was used to guide settlements of religious warfare in 1555 and 1648. At the Peace of Augsburg in 1555, it was agreed that territories under Roman Catholic government would remain Roman Catholic and that those governed by Lutherans would remain Lutheran. Nearly one hundred years later at the Peace of Westphalia the same principle was applied, this time including Calvinists as well as Roman Catholics and Lutherans. This agreement sanctioned and prepared the way for the survival of established churches in Europe up to the present.