This personal copy from the private library of Scottish historian and essayist, Thomas Carlyle (1795–1881), was donated to Harvard in 1881, per the author’s will and his inscription on the end paper in the front matter. A specialist and admirer of German literature and author of a six-volume biography of Frederick the Great, “History of Friedrich II of Prussia, called Frederick the Great” (1858–1865) [HOLLIS 002854241], Carlyle took particular interest in the life and work of French philosopher Voltaire and his influence on the Prussian monarch. Carlyle’s annotations throughout the book indicate events in Voltaire’s life that Carlyle explored in preparation of his biography. They further provide a source for his critical evaluation of Voltaire in “Character and Genius of Voltaire” [Hollis 006843759]. Carlyle’s comments render this copy unique and it is, therefore, held at Houghton Library, together with other titles from Carlyle’s private library. Exclamations and cross-references entered in English in pencil in the margins show how Carlyle read closely this biographical account of Voltaire's stay in Frankfurt am Main by Karl August Varnhagen von Ense (1785-1858).