Wilhelm Heinrich, Duke of Saxe-Eisenach

As an 18-year-old, he barely survived a fall from a horse, but sustained a severe kidney injury that would plague him for the rest of his life. In 1729, after the death of his father, he ascended the ducal throne of Saxe-Eisenach.

As early as 1723, through his marriage to a Prussian princess, knight of the Order of the Black Eagle, he showed great interest in everything military. He gave two of his Eisenach regiments into foreign service, for example in the Netherlands and in the Imperial Army. On October 17, 1740, he also promised his nephew by marriage, the Prussian king Friedrich II., another regiment, the later Füsilierregiment No. 40. That already in 1732 The regiment, which was set up with two musketeer battalions, had already fought in the War of Succession to the Polish throne, in imperial service on the Rhine, in northern Italy and on Lake Constance, since 1734 with three battalions. After the Vienna Peace and the return to Eisenach in 1739, it was reduced to a battalion; most officers retired. Sworn to Prussia on October 8, 1739, it was taken over in Magdeburg in 1740 by Colonel Christian Reinhold von Derschau. The duke enlisted 25 non-Eisenachian officers, procured replacements for the second battalion, and became chief of the regiment.

He was buried in the Georgenkirche in Eisenach. With his death, the family of the dukes of Saxony-Eisenach died out, and the principality became an inheritance to Saxony-Weimar. Since then, the two countries were united and known as the Duchy, from 1815 Grand Duchy Saxony-Weimar-Eisenach.

Wilhelm Heinrich was married twice. In his first marriage he married Albertine Juliane von Nassau-Idstein in 1713. In his second marriage he married Anna Sophie Charlotte von Brandenburg-Schwedt in 1723. Both marriages remained childless.

• Siegrid Westphal: A prince is looking for his fortune – the class lottery under Wilhelm Heinrich von Sachsen-Eisenach (1691–1741) . In: Annette C. Cremer, Alexander Jendorff (eds.): Decorum and mammon in conflict? Aristocratic economic activity between class profiles, striving for profit and economic necessity (interdisciplinary courtly culture - writings and materials of the Rudolstadt working group on residence culture, vol. 4), Heidelberg University Publishing: Heidelberg 2022, ISBN 978-3-96822-069-7, p. 365-378.