In 1561, the Naumburg Diet recognized the unaltered Augsburg Confession and is recognized as part of the pre-history of the Book of Concord. The ecclesiastical domain was secularised in middle of the 16th century and transferred to the Dukes of Saxony, who administered the district through a government endowment ("Stiftsregierung") and later provided administrators. After the fraternal agreement between the four brothers of John George I, Elector of Saxony, in 1657 the Naumburg district came into the possession of the secondogeniture of Saxe-Zeitz, which was inherited by Moritz, the youngest of the brothers.