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. Its capital was the town of Altenburg. During its existence, Saxe-Altenburg was known for its cultural contributions and its picturesque landscapes. The duchy had a population of around 100,000 people and was characterized by its agricultural economy. Following the end of World War I, the duchy was dissolved, and its territory became part of the newly formed Free State of Thuringia.