Friedrich von Anhalt
Son of Count William Gustav (1699-1737) of Anhalt-Dessau and Johanna Sophie Herre (1706-1795).
Count Friedrich was sometime aide-de-camp to King Friedrich II of Prussia and rose to become his Adjutant-General.1 In 1776, after six years as a General-Major and with no immediate prospects of promotion, he left the Prussian army. In 1783 he entered the service of the Russian Empress, and died in St. Petersburg on June 2, 1794 - at his death he was General-Adjutant to the Empress Katharina the Great, and Director-General of the Landcadettencorps.2
Boswell met the Count of Anhalt at Potsdam on July 3, 1764. Boswell described him as "the lover of Zélide", that is Belle de Zuylen, Boswell's close friend from his year in Utrecht. A footnote in Boswell on the Grand Tour I even mentions the Duke having proposed to Zélide, without having ever met her.
On September 24, 1764, Boswell delivered a letter from the Count to a cousin of his, Johann Georg, at Dessau, and on the next day, he was introduced to his mother, the Countess Johanna of Anhalt.