The Nuttall Encyclopedia
Ziethen, Johann Joachim von
Prussian general, born in Russia; entered the army at the age of 15, served as a cavalry officer under Frederick the Great, was one of the greatest of his generals, became his personal friend, and contributed to a great many of his victories, all of which he lived through, spending his days thereafter in quiet retirement at Berlin in favour with the people and in honour to the last with the king; is described by Carlyle at 45 as "beautiful" to him, though with "face one of the coarsest," but "face thrice-honest, intricately ploughed with thoughts which are well kept silent (the thoughts indeed being themselves mostly inarticulate, thoughts of a simple-hearted, much-enduring, hot-tempered son of iron and oatmeal); decidedly rather likeable" (1699-1786). See Carlyle's "Frederick."
Wood, James, ed. Entry for 'Ziethen, Johann Joachim von'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/z/ziethen-johann-joachim-von.html. Frederick Warne & Co Ltd. London. 1900.