Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. John Ernest, Duke of Saxe-Coburg-Saalfeld (b. Gotha, 22 August 1658 - d. Saalfeld, 17 February 1729) was a duke of Saxe-Coburg-Saalfeld. He was the tenth but seventh surviving son of Ernest I, Duke of Saxe-Gotha and Elisabeth Sophie of Saxe-Altenburg. After the death of his father in 1675, John Ernest initially governed the duchy of Saxe-Gotha-Altenburg, jointly with his six older brothers, as set out in their father''s will. However, in 1680 the brothers concluded a treaty dividing the paternal lands and John Ernest became duke of Saxe-Saalfeld, with the towns of Gräfenthal, Probstzella and Pössneck.