A ground-breaking look at a very neglected subject, the practice of intelligence in naval warfare during the Age of Sail. The author deals with a wide range of subjects, from “The British National Intelligence Effort,” which proves to have been extremely effective, to signals technology, deception, reconnaissance, and, in what is perhaps the most valuable portion of the book, the role of the commander.

Maffeo points out that senior naval officers were their own chiefs of intelligence, a task at which some were better than others. He particularly singles out Nelson as an extremely able intelligence manager, using numerous examples of his surprisingly incisive logical approach to matters of intelligence. The book concludes with three examples of British naval intelligence successes, Pulo-Aur in the Indian Ocean in 1804, Copenhagen in 1801, and the campaign of the Nile in 1798, respectively on a tactical, operational, and strategic level. Most Secret and Confidential, which is not afraid to use references to the well-researched treatments of such fictionally famous admirals as Hornblower and Aubrey, would make useful reading for anyone interested in sea power in the age of sail, the wars of the French Revolution and Napoleon, and the history of intelligence.