Frederick Henry Eugen, Prince of Anhalt-Dessau
Son of Leopold I of Anhalt-Dessau (1676-1747) and Anna Luise Föhse (1677-1745).
He entered into Prussian military service in 1717, and from 1736 to 1739 was Chef des Korps of the 1st Prussian Horse Regiment. In 1743 he left Prussian service and joined the Austrian army under Prince Karl of Lothringen as a volunteer. In 1746 he entered into the service of the Kingdom of Saxony, where he eventually became Governor of Wittenberg and, later, Field Marshall.
Boswell was introduced to Prince Eugen at Dessau on September 29, 1764, and described him as "a Saxon general, and a most curious figure, quite a countenance of the last age, venerable and yet queer. Had he been hung up on the side of the room, you would have sworn it was a portrait by a master long since dead."