John I, Duke of Saxony German duke (1249–1285) Parents Helene of Brunswick-Lüneburg Albert I, Duke of Saxony Children Eric I, Duke of Saxe-Lauenburg John II, Duke of Saxe-Lauenburg Elisabeth of Saxe-Lauenburg Albert III, Duke of Saxe-Lauenburg Helena of Saxe-Lauenburg Siblings Jutta of Saxony Albert II, Duke of Saxony Brigitte Jutta of Saxony Helena of Saxony Helene von Sachsen Bernhard von Sachsen Elisabeth von Sachsen Agnes von Sachsen Partners Ingeborg Birgersdotter of Bjelbo