See also Recurring characters in the Aubrey–Maturin series
- Jack Aubrey: Appointed Commodore in the Royal Navy.
- Stephen Maturin: Surgeon of the Bellona , physician, natural philosopher, friend to Jack and an intelligence officer.
- Heneage Dundas: Captain of HMS Berenice , brother to the first Sea Lord, and friend of Aubrey.
- Preserved Killick: Aubrey's steward.
- Barret Bonden: Coxwain for Aubrey.
- Mr David Adams: Captain's clerk on Surprise , then Secretary for the Commodore on Bellona .
- Padeen Colman: Irish servant to Maturin.
- Sarah and Emily Sweeting: Melanesian girls rescued earlier by Maturin (in The Nuutmeg of Consolation ), rated as ships boys; set up in The Grapes under Mrs Broad's care.
- Duke of Habachtsthal: Last British official feeding information to the French and endangering Maturin and Blaine personally. He was a homosexual lover of Ledward and Wray, killed earlier. He is minor royalty in the British line, with property in a German state (now held by the French) and in Ireland. He kills himself at the end of this story, reason not explained; perhaps Mr Pratt's investigations threatened his exposure or his own agents were turning on him.
- Awkward Davies: Able seaman.
- Joe Plaice: Able seaman and cousin to Bonden.
- Fellowes: Captain of HMS Thunderer .
- Mr Philips: Admiralty officer aboard the Thunderer with a message for Maturin.
- Sophia Aubrey: Wife of Jack and mother of their three children.
- Fannie and Charlotte Aubrey: Twin daughters of Jack and Sophia.
- George Aubrey: Young son of Jack and Sophia.
- Mrs Williams: Mother of Sophia and aunt to Diana Villiers, a mean and gossiping woman, trying to interfere with Brigid's upbringing.
- Mrs Selina Morris: Friend and companion to Mrs Williams, of the same character.
- Mr Briggs: Servant to Mrs Morris and money man for her and Mrs Williams, as the three take bets on horses.
- Diana Villiers: Stephen's wife and mother of their child.
- Clarissa Oakes: Young gentlewoman, widow of Lieutenant William Oakes, now part of Maturin's household, introduced in Clarissa Oakes .
- Brigid Maturin: Young daughter of Stephen and Diana, showing developmental problems, until Padeen enters her life; nickname Brideen.
- Aunt Petronilla: Aunt to Maturin who heads a Benedictine convent in Avila, where his daughter, Clarissa and Padeen will stay.
- Mr Hinksey: Priest for the parish including Ashgrove Cottage, helpful to Mrs Aubrey, and about to be married.
- Sir Joseph Blaine: Head of Intelligence at the Admiralty, naturalist who studies beetles, and friend of Maturin.
- Mr Pratt: Investigator ("thief taker") introduced in The Reverse of the Medal .
- Mr Brendan Lawrence: Lawyer for Aubrey, and advisor to Maturin in responding to the Duke, introduced in The Reverse of the Medal .
- Mnason: Jack's butler at Woolcombe.
- William Smith: First assistant surgeon on Bellona , with experience in Bridgetown.
- Alexander Macaulay: Second assistant surgeon on Bellona , fresh from his training.
- Mr Wetherby: Youngster on Bellona .
- Mr William Reade: Midshipman, about age 15, on HMS Bellona , who lost an arm in battle; introduced in The Thirteen Gun Salute . He sails the Ringle , Aubrey's personally-owned tender, a fast-sailing Baltimore clipper.
- Mr Gray: First Lieutenant on the Bellona , who dies from infection after surgery.
- Mr William Harding: Second Lieutenant on the Bellona , moves up to first on the death of Mr Gray.
- Mr Whewell: Acting third Lieutenant on the Bellona , promoted from master's mate on the Aurora due to his knowledge relevant to the mission.
- John Paulton: Friend met in New South Wales who assisted in kinder treatment and escape of Padeen Colman in The Nutmeg of Consolation ; his novel is published, and dedicated to Stephen Maturin, as reported by some in the squadron who read it.
- Mr Willoughby: Marine Lieutenant aboard HMS Stately , who is insulted at dinner by the 2nd Lieutenant of HMS Thames .
- William Duff: Captain of HMS Stately; he loses a leg in the action against the French squadron in Bantry Bay in Ireland.
Met at Freetown
- John Square: Krooman who assists Maturin during the first mission of the squadron.
- Houmouzios: Greek money lender in the market at Freetown who takes messages for Maturin.
- James Wood: Colonial Governor at Freetown in Sierra Leone with experience in the Royal Navy.
- Mrs Wood: Born Christine Hatherleigh, she is the sister of Edward, who is an eminent naturalist. She shares her brother's interest and knowledge.
Met in West Cork
- Esprit-Tranquille Maistral: Commodore of the French squadron headed to Bantry Bay in West Cork in Ireland.
- Mr Frank Geary: Captain of HMS Warwick , posted at Bere Haven, which they left on hearing reports of gunfire.
- Father Boyle: Ashore in Ireland where the French ship grounded, he aids in bringing the wounded to hospitals on land.
- Stanislas Roche: Local man in West Cork, old friend to Maturin, who explains why the flags are at half-mast, and takes him where Diana Villiers is staying, at the home of a relative of her late husband.
Squadron leaders
- Captain Tom Pullings: Bellona
- Captain William Duff: Stately
- Captain Thomas (nicknamed the Purple Emperor ): Thames
- Captain Francis Howard: Aurora
- Captain Michael Fitton: Nimble
- Captain Smith: Camilla
- Dick Richardson (introduced in The Mauritius Command ): Laurel
