BiographyJohann Wilhelm von Sachsen-Jena, Herzog von Sachsen-Jena, was born 28 March 1675 in Jena, Thuringia, Germany to Bernhard von Sachsen-Jena (1638-1678) and Marie Charlotte de La Trémoille (1632-1682) and died 4 November 1690 in Jena, Thuringia, Germany of unspecified causes. Notable ancestors include Henry II of England (1133-1189), William I of England (1027-1087), Charlemagne (747-814), Hugh Capet (c940-996), Willem van Oranje (1533-1584), Alfred the Great (849-899), Rurik (c832-879). Ancestors are from Germany, France, the United Kingdom, the Netherlands, Denmark, Poland, Austria, Belgium, Belarus, Russia, Ukraine, Spain, Italy, Switzerland, Lithuania, Portugal, the Czech Republic, Hungary, Bohemia, Slovakia, Slovenia, England, Turkey, the Byzantine Empire, Sweden, the United States.
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.