Magnus IV of Sweden
King Erik's grand daughter, Ingeborg Håkansdotter, inherited the area from her father, King Haakon V of Norway. She and her husband, Erik, Duke of Södermanland, established a semi-independent state out of their Norwegian, Swedish and Danish counties until the death of Erik. They spent considerable time at the fortress. Their son, King Magnus IV of Sweden (Magnus VII of Norway), spent much time at the fortress as well.