Johann Adolf of Saxe-Gotha-Altenburg

Johann Adolf of Saxe-Gotha-Altenburg (18 May 1721, Gotha– 29 April 1799, Friedrichstanneck, now a district of Eisenberg, Thuringia), was a German prince of the House of Saxe-Gotha-Altenburg and a Saxon lieutenant general.

Johann Adolf was the youngest son of Frederick II, Duke of Saxe-Gotha-Altenburg and Magdalene Augusta of Anhalt-Zerbst. Since 1735 the prince was educated in Geneva and joined the Danish military service in 1739. On his Grand Tour he visited his sister Augusta in the United Kingdom where he also obtained a Ph.D. from the University of Oxford.

In 1743 he moved to the Saxon army to become holder of a regiment the following year and fought at the Battle of Hohenfriedberg. He became major general in 1746 and established his headquarter in Naumburg. In 1748 he obtained the Polish Order of the White Eagle and became Saxon lieutenant general in 1753. During The Seven Years' War he was captured be the Prussian Army and had to swear not to fight the Prussians further before being released. Later, the Prussian Army tried to absorb his regiment.

Johann Adolf retired to Eisenberg where he had the house Markt 25 built in 1750. In 1756 he had built Schloss Friedrichstanneck nearby. After Prince Joseph of Saxe-Hildburghausen died in 1787 he became Elder of the Ernestine line of the House of Wettin, a position already hold by his older brother Frederick III until his death in 1772. Because of this position he obtained Oldisleben territory. After Johann Adolf died in 1799 Prince Josias of Saxe-Coburg-Saalfeld became Elder of Ernestine Wettin and received the Oldisleben territory. Johann Adolf is buried at the chapel of Christiansburg Castle in Eisenberg.

The Ernestine duchies of Saxe-Gotha-Altenburg and Saxe-Weimar considered a marriage between Johann Adolf and Princess Ernestine Albertine of Saxe-Weimar-Eisenach, daughter of Ernest Augustus I, Duke of Saxe-Weimar-Eisenach. The negotiations delayed over the dowry. In the meantime Ernestine Albertine decided for Philip II, Count of Schaumburg-Lippe. Johann Adolf later married Marie Maximiliane Elisabeth Schauer morganatically. They had three children of which two survived.

• Friedrich Adolph (*/+1760)
• Adolph Christian Carl (1761–1835)
• Johanna Adolfine Friederike (1767–1804)

Marie Maximiliane Elisabeth Schauer was ennobled together with her two children on January 12, 1779 by Joseph II, Holy Roman Emperor.