Saxe-Gotha-Altenburg was a duchy ruled by the Ernestine branch of the House of Wettin in today's Thuringia, Germany. The extinction of the line in 1825 led to a major re-organisation of the Thuringian

Frederick I, Duke of Saxe-Gotha-Altenburg, was a territorial ruler in Thuringia from the Ernestine branch of the House of Wettin. He continued the line of Saxe-Gotha founded by Ernest I, his father, w