 After 1369, the Schultheiss-Ribi family were tenants of the castle.In 1375 the castle underwent a siege by the Gugler.The latent tensions between Sigismund, King of Germany and Frederick IV, Duke of Austria exploded in 1415 at the Council of Constance, when Frederick assisted one of the three then reigning popes, Antipope John XXIII, in escaping from the town.