Sigismund succeeded his elder brother,
Frederick, in 1552 as prince-archbishop of
Magdeburg and
diocesan administrator of the
Prince-Bishopric of
Halberstadt. The administration of the Halberstadt see had been combined with the Magdeburg see since 1480. Because he was only 14 it was initially suggested that the
Magdeburg Cathedral chapter could not elect him, so he was postulated. Until 1557, when he came of age, Count John George of Mansfeld was installed by the
cathedral chapter to run the prince-archbishopric. On 21 January 1553 the young prince-archbishop, who had meanwhile been confirmed by Pope
Julius III although he was
Lutheran, was rendered homage by the nobility in
Halle upon Saale. In the early years of the new
schism the Holy See was not always aware who was seriously Lutheran, and still hoped the schism would abate again. Although Lutheran, Sigismund remained unmarried. In 1567 the remainder of the cathedral chapter converted to Lutheranism. In 1555 Sigismund issued a code of procedure. Three years later, Emperor
Ferdinand I granted the prince-archbishop the
privilegium de non appellando. From 1552 to 1553 Sigismund had a new residence, the Peterhof, built in
Halberstadt. == Death ==