"Notes and necessary explanations to Mr. S.Y. Holm's notes on campaigns against Russia in 1808 and 1809" is a detailed study of the history of military events that took place during the era of the Napoleonic Wars. The author Gustav Magnus Adlerkreutz carefully analyzes the events that took place during this period and their impact on the course of world history. The book is an important source for understanding the political and military aspects of the conflict between Sweden and Russia during this period and for the general study of European history before the 19th century.