In 1546 he joined the government of the county of Lippe and during his reign, he tried especially to strengthen the Lutheran faith in his county. This met with disapproval of the Emperor Charles V, whose troops occupied Lippe in the course of the Schmalkaldic War (1546–1547) and after the defeat of the Protestant side in 1548, began implementing the Augsburg Interim. As a result, Lippe became an imperial fief.