While the relatively lenient stance of the archbishops of Salzburg had allowed the creation of small pockets of Protestantism in their lands since the Protestant Reformation, the remaining Protestants were oppressed more harshly during the Habsburg rule of the 19th century. In 1837, 437 Protestant inhabitants of the Ziller Valley left the valley after they were given the choice of renouncing the Augsburg Confession or emigrating to Silesia, where Frederick William III of Prussia offered them lands and housing near Erdmannsdorf (now Mysłakowice in western Poland).