Fedor Feodorovich Tornau, who was born into a military family in a region that is today within the borders of Belarus, participated in the Ottoman-Russian War of 1828-1829 as a young lieutenant at the age of 18. Tornau, who rose to the top ranks in a short time with his successes in this war, especially in the field of intelligence, later served in various missions in the Caucasus. Tornau spent the last part of his life as an agent in Vienna and died on January 7, 1890, in Vienna. F.F. Tornau wrote his memoirs about the Ottoman-Russian War of 1828-1829, many years after the war, in 1867. In this memoir, which was published in two parts in the journal Russkiy Vestnik (Tornau, 1867: 5-64), which we can translate as Russian Bulletin, F.F. Tornau, who participated in the Ottoman-Russian War of 1828-1829 as a young lieutenant at the age of 18, conveyed his observations about the operations, conflicts and the Russian army. Although the reliability of this memoir, which is the subject of this article, is questionable since it was writ-ten years after the war, the fact that it describes the clashes between the Ottoman Empire and the Russian Empire forces through the eyes of a Russian lieutenant makes this memoir an important source for this war. Interestingly, however, the young lieutenant does not give much information about the dates of the events in his memoirs. This is probably because the memoir was written around 37 years after the war, and he could not remember the exact dates. Tornau wrote about his duties during the war and the battles he fought, and this memoir and other memoirs he wrote during his other duties were combined and published as a book in 2017. In addition to my recollections of the War with the Turks in the Danube and the Balkans, the subject of this article, and the campaign of 1829, this study also includes the Polish operation of 1832, the narratives of an Arme-nian lieutenant from Vienna to Karslbad (Baden-Germany), impressions of the journey from Vienna to Karslbad, and Tornau’s recollections of Vienna in 1859 (Tornau, 2017).