In the aftermath of the Reformation in Norway, the structure was renamed Hamarhus and became the residence of the local sheriff. Although still used, the cathedral fell into disrepair, which culminated with its besiegement by the Swedish army and attempted demolition in 1567 during the Northern Seven Years' War. Swedish forces had launched attacks into Eastern Norway, capturing Hamar and continued towards Oslo. The Swedes later retreated, torching Hamar on their way, destroying Hamar Cathedral and Hamarhus.