Dorothea of Brandenburg, Duchess of Saxe-Lauenburg Duchess of Saxe-Lauenburg (1446–1519) Parents Catherine of Saxony, Electress of Brandenburg Frederick II, Elector of Brandenburg Children Magnus I, Duke of Saxe-Lauenburg John IV of Saxe-Lauenburg Eric of Saxe-Lauenburg Elisabeth von Sachsen-Lauenburg Bernhard von Sachsen-Lauenburg Siblings Margaret of Brandenburg Partners John V, Duke of Saxe-Lauenburg