The Duchy of Saxe-Altenburg was a small German state that existed from 1826 until 1918. It was part of the larger Saxe region and was located in central Germany. The duchy was established when the former Duchy of Saxe-Gotha-Altenburg was divided, and it was ruled by the House of Saxe-Altenburg. The capital city was Altenburg, which served as the political and cultural center of the duchy. Throughout its history, Saxe-Altenburg was known for its rich cultural heritage and contributions to the arts. The duchy was relatively small in size and population, but it played a role in the broader political landscape of Germany, especially during the unification period in the 19th century. After World War I, the duchy was dissolved, and its territory became part of the newly formed Free State of Thuringia.