The people of Hadeln, represented by their estates of the realm, adopted the Lutheran Reformation in 1525 and Duke Magnus I confirmed Hadeln's Lutheran Church Order in 1526, establishing Hadeln's separate ecclesiastical body existing until 1885. Magnus did not promote the spreading of Lutheranism in the rest of his duchy. Lutheran preachers, most likely from the southerly adjacent Principality of Lunenburg, Lutheran since 1529, held the first Lutheran preaches; at the northern entrance of St. Mary Magdalene Church in Lauenburg upon Elbe one is recalled for St John's Eve in 1531. Tacitly, the congregations appointed Lutheran preachers so that the visitations of 1564 and 1566, ordered by Duke Francis I, Magnus I's son, on the instigation of the Ritter- und Landschaft, saw already Lutheran preachers in many parishes. In 1566, Francis I appointed the Superintendent Franciscus Baringius as the first spiritual leader of the church in the duchy, not including Hadeln.