William Babbington is a in Jack Aubrey's first command, HMS Sophie. As a midshipman, Babbington has an almost insatiable lust for the fairer sex. Stephen Maturin notes that Babbington's stunted growth is likely the result of his frequent encounters, at an early age, with poxed ladies of the evening. Babbington later is made a commander, and then a post captain, both because of his natural ability (augmented by having been trained by Aubrey), and because he has influential relations who control several seats in Parliament. As a Commander of the ship in which Maturin and Diana travel back from Paris, he solemnises their marriage. Babbington himself later falls in love with Admiral Harte's daughter, inconveniently married to the traitorous Andrew Wray.