The town of Lüneburg supported the Wittenbergs and took the opportunity to escape from the immediate influence of the duke, destroying the ducal castle on the "Kalkberg" on 1 February 1371 and forcing him to relocate his residence to Celle. An attempt on 21 October 1371, St. Ursula's Day, to overthrow Lüneburg militarily and to secure the old ducal rights, failed. In the military conflict that followed, neither the Brunswicks nor the Wittenbergs were able to enforce their claims, and only the peace of Hanover in 1373, ended the war, at least for a time. According to the agreement reached there, the Welfs and the Wittenbergs were to rule alternately.