The book "The Messenger of Adlerkraits: The Case of the Battle of Revonlacht in 1808" by the Swedish writer J. O. (Johan Olof) Eberg tells about the events of the Finnish War of 1808–1809. This historical book reveals the dramatic events during the Battle of Revonlacht, which became a key factor in bringing Sweden and Russia together on Finnish territory. The author explores in detail the place of this event in history and reproduces portraits of key figures and cultural contexts of that time. "The Messenger of Adlerkraits" is a fascinating historical book that reveals to the reader the complex relationships that determined the events of that period.