Beginning in the 11th century, the Bishops of Chur began taking sides in secular conflicts as their worldly power grew. In 1079/80, during the Investiture Controversy the emperor's candidate Norbert became bishop over the pope's candidate Ulrich II of Tarasp. He held the office until 1087, when he was replaced by Ulrich II.During the conflicts between Frederick Barbarossa and Pope Alexander III following the 1159 papal election, Bishop Egino of Chur sided with the emperor and was rewarded with the dignity of Prince of the Empire (1170).In 1514 Emperor Maximilian I separated the land surrounding the cathedral from the town of Chur and granted it as an imperial estate to the Bishops.In 1524 the Protestant Reformation was accepted in Chur and the two Catholic churches of St. Martin and St. Regula were given over to the Protestants. The bishop fled, and his administrator, Abbot Theodore Schlegel, was publicly beheaded (1 January 1529). Bishop Thomas Planta, tried without success, to suppress Protestantism. He died, probably poisoned, 5 May 1565.The Ilanz Articles of 1524 restricted the secular power of the bishop to his imperial estate, including the cathedral. During the Bündner Wirren, the cathedral remained a center of Catholic power in the region. The 1803 Act of Mediation ended the secular power of the bishop.