The Duke of Saxe-Lauenburg was a title held by the rulers of the duchy located in northern Germany. This region was part of the larger territory of the historic state of Saxony and was established in the late Middle Ages. The dukes played a significant role in the political landscape of the Holy Roman Empire and were involved in various alliances and conflicts. The duchy was eventually absorbed into the larger territories of Saxony and Schleswig-Holstein. The last duke, Francis II, ruled until the dissolution of the duchy in the 19th century. Today, the title is considered a historical reference rather than an active nobility.