The Duchy of Saxe-Lauenburg was a historical territory in northern Germany, part of the larger Saxony region. Established in the late Middle Ages, it became a duchy in the 15th century and was ruled by various branches of the House of Ascania. The duchy was known for its strategic location along trade routes and its rich cultural heritage. Throughout its history, Saxe-Lauenburg experienced territorial changes and political alliances, particularly during the Thirty Years' War. In 1701, it was incorporated into the Duchy of Saxe-Gotha-Altenburg, marking the end of its status as an independent duchy. Today, the region is part of the modern state of Schleswig-Holstein.