Based on the original sources, the article considers the life and activities of Patrick Gordon, a Scottish officer who served in the Russian Tsarist army in the second half of the 17th century. While Gordon’s biography has been extensively studied by historians, his “secret” activities have not beenthe subject of scholarly research. The authorfocuses on Gordon’stestimonies,which are preserved in his diaries, about hismeetings with the King and high-ranking English officials, as well as his secret correspondence with the Secretary of State responsible for foreign policy. These facts allowed the author to argue that Gordon, while serving the tsar, was not only engaged in military activities but also in espionage for the British.