Johann Wilhelm, Duke of Saxe-Jena

Johann Wilhelm, Duke of Saxe-Jena (Jena, 28 March 1675 – Jena, 4 November 1690), was a duke of Saxe-Jena.

Johann Wilhelm
Duke of Saxe-Jena
Reign	1678–1690
Predecessor	Bernhard II
Successor	Duchy divided between Saxe-Weimar and Saxe-Eisenach
Born	28 March 1675 Jena
Died	4 November 1690 (aged 15) Jena
House	House of Wettin
Father	Bernhard II, Duke of Saxe-Jena
Mother	Marie Charlotte de la Trémoille
Religion	Lutheran

He was the youngest but sole surviving son of Bernhard II, Duke of Saxe-Jena by his wife Marie Charlotte, daughter of Henry de La Trémoille, 3rd Duke of Thouars, 2nd Duke of La Tremoille, and Prince of Talmond and Taranto.

Life

When only three years old (1678) he succeeded his father as Duke of Saxe-Jena. In accordance with the testamentary instructions of his father, his uncle, Duke Johann Ernst II of Saxe-Weimar assumed his guardianship and the regency of the duchy; when he died in 1683, another uncle, Duke Johann Georg I of Saxe-Eisenach, assumed the regency. Three years later (1686), the new regent also died, and his cousin (son of the late Duke Johann Ernst II) and brother-in-law (he was married to his eldest and only surviving sister, Charlotte Marie) Duke Wilhelm Ernst of Saxe-Weimar was appointed to the regency.

As Johann Wilhelm lived only fifteen years and failed to reach adulthood, he never governed. With his death the line of the Dukes of Saxe-Jena had become extinct, and the duchy was divided between Saxe-Weimar and Saxe-Eisenach.