The House of Saxe-Altenburg is a German noble family that originated in the 17th century. It was a branch of the larger House of Saxe, which played a significant role in the history of the German states. The family ruled the Duchy of Saxe-Altenburg, which was established in 1603 and became part of the larger Saxe-Weimar-Eisenach in 1920. Members of the House of Saxe-Altenburg held various titles and positions within the German nobility. The family is known for its contributions to the cultural and political landscape of the region, including connections to other noble houses and involvement in the German Confederation.