The Letter of Marque

The Letter of Marque is the twelfth novel of the Aubrey-Maturin series by the English writer Patrick O'Brian, first published in 1988. Like the rest of the series it is set during the Napoleonic Wars and the War of 1812, and it takes up the consequences of the loss of Aubrey's post captaincy.

No longer a post captain, Aubrey is free to take the ship he knows best to sea, and the Surprise sails under a letter of marque, the licence that lets a privately owned vessel take enemy shipping as prizes. Maturin, who has bought her and now owns her outright, comes aboard in his old role of surgeon and natural philosopher, and the two of them put together a crew from the privateers and smugglers of the western coast.

The cruise begins as a straightforward piece of commerce, with the promise of prize money for everyone aboard and a chance for Aubrey to rebuild a reputation that his enemies on shore have damaged. It is when the ship turns into French waters that the voyage becomes something more deliberate, and the book follows the two friends through a scheme intended to clear his name.