John William III, Duke of Saxe-Eisenach

Johann Wilhelm, Duke of Saxe-Eisenach (b. Friedewald, 17 October 1666 - d. Eisenach, 14 January 1729), was a duke of Saxe-Eisenach.

He was the third son of Johann Georg I, Duke of Saxe-Eisenach and Johannetta of Sayn-Wittgenstein. His twin brother, Maximilian, died with two years.

He succeeded his brother Johann Georg II as duke of Saxe-Eisenach when he died in 1698.

In Oranjewoud on 28 November 1690, Johann Wilhelm married with Amalie of Nassau-Dietz, who was eleven years older. They had two children:
#Wilhelm Heinrich, Duke of Saxe-Eisenach (b. Oranjewoud, 10 November 1691 - d. Eisenach, 26 July 1741).
#Albertine Johannetta (b. Oranjewoud, 28 February 1693 - d. Eisenach, 1 April 1700).

In Wolfenbüttel on 27 February 1697 -after two years of the death of his first wife-, Johann Wilhelm married secondly with Christine Juliane of Baden-Durlach. They had seven children:
#Johannette Antoinette Juliane (b. Jena, 31 January 1698 - d. Schloss Dahme, 13 April 1726), married on 9 May 1721 to Duke Johann Adolf II of Saxe-Weissenfels.
#Karoline Christine (b. Jena, 15 April 1699 - d. Philippsthal, 25 July 1743), married on 24 November 1725 to Ldgve Karl I of Hesse-Philippsthal.
#Anton Gustav (b. Eisenach, 12 August 1700 - d. Eisenach, 4 October 1710).
#Charlotte Wilhelmine Juliane (b. Eisenach, 27 June 1703 - d. Erfurt, 17 August 1774).
#Johannetta Wilhelmine Juliane (b. Eisenach, 10 September 1704 - d. Eisenach, 3 January 1705).
#Karl Wilhelm (b. Eisenach, 9 January 1706 - d. Eisenach, 24 February 1706).
#Karl August (b. Eisenach, 10 June 1707 - d. Eisenach, 22 February 1711).

In Weissenfels on 28 July 1708 -after one year of the death of his second wife-, Johann Wilhelm married thirdly with Magdalene Sibylle of Saxe-Weissenfels. They had three children:
#Johanna Magdalene Sophie (b. Eisenach, 19 August 1710 - d. Eisenach, 26 February 1711).
#Christiane Wilhelmine (b. Altenkirchen, 3 September 1711 - d. Idstein, 27 November 1740), married on 26 November 1734 to Prince Karl of Nassau-Usingen.
#Johann Wilhelm (b. Marksuhl, 28 January 1713 - d. Eisenach, 8 May 1713).

In the Schloss Philippsruhe on 29 May 1727 -after one year of the death of his third wife, Johann Wilhelm married fourthly with Marie Christine Felizitas of Leiningen-Heidesheim, Dowager Princess of Baden-Durlach. This union was childless.