The Protestant Reformation began in 1517, but its effects were to last far longer. The authority of the Catholic Church in Europe was in question for the first time in a long time, and the continent divided into Catholics and Protestants. While some countries were more clearly Protestant, such as England and the Netherlands, and others remained staunchly Catholic like Spain, still others were marked by acute internal division. Martin Luther’s Reformation sharply divided German princes within the Holy Roman Empire, leading to conflict between the Catholic Hapsburg emperors and the princes (primarily in the northern part of the Empire) who adopted Lutheran Protestantism. This led to several conflicts that ended with the Peace of Augsburg (1555), which established the principle of cuius regio, eius religio (whoever reigns, his religion) within the Holy Roman Empire. According to the terms of the Peace of Augsburg, the Holy Roman Emperor renounced the right to enforce a single religion throughout the “Empire” and each prince could choose between establishing Catholicism or Lutheranism in the lands under his own control.