THIS BOOK STUDIES PART OF BRITAIN'S early-nineteeth-century supremacy at sea and the Royal Navy's use of maritime blockades and convoys as economic warfare against a United States republic not yet thirty years old. It is not a general history of the War of 1812; rather, it briefly traces the evolution of both offensive and defensive economic warfare at sea, and then examines Britain's aggressive use of commercial and naval blockades, and the protective use of merchant convoys, during it. This strategy had evolved during a succession of wars, and was to prove particularly successful when used by Britain in the Anglo-American war of 1812–15 – the so-called ‘War of 1812’. This was, in effect, part of Britain's long-term war with France, declared by the French Revolutionary government in February 1793 and continued by Napoleon until his downfall. Apart from a brief respite during the Peace of Amiens, between March 1802 and May 1803, it was to last until the autumn of 1815, when Napoleon was finally and permanently exiled on St Helena.

During Britain's war with France French military successes in Continental Europe could be contained only by British seapower. Britain possessed not only the world's largest merchant fleet but also the Royal Navy, the world's strongest maritime fighting force. Britain's maritime commercial blockade of France had isolated her colonies, dislocated her overseas trade and seriously damaged the French economy, while the Royal Navy's blockades of French ports had prevented the amalgamation of France's Brest and Toulon fleets, making the invasion of Britain impracticable and the military reinforcement of French colonies extremely difficult.