Saxe-Gotha (German: Sachsen-Gotha) was one of the Saxon duchies held by the Ernestine branch of the Wettin dynasty in the former Landgraviate of Thuringia. The ducal residence was erected at Gotha.It was established in 1640, when Duke Wilhelm von Saxe-Weimar created a subdivision for his younger brother Ernest I the Pious. Duke Ernest took his residence at Gotha, where he had Schloss Friedenstein built between 1643 and 1654.