A review of the book by S. A. Mezin and the publication of an interesting historical source written in 1757 by Chevalier d’Eon, a diplomat and adventurer is presented. The manuscript “Secret Anecdotes about the Court of the All-Russian Empress” is published for the first time both in French and in Russian. In the peer-reviewed book the source characteristic and the analysis of the manuscript, scientific comments, the detailed essay on French studies of Russia in 1725–1762 were qualitatively made.
