French compositional treatises penned between c.1600 and c.1750 rarely if ever provide any instructional exercises with basses, from which apprentice composers could create multi-voice pieces by applying the rules described by their authors. Instead, these treatises—of which the most famous and widespread were no doubt those by Parran (1639), Mignot (1656), Masson (1697) and Rameau (1722)—reproduce a number of more or less extended examples to illustrate particular theoretical points. Nicolas Bernier’s handwritten ‘Principes de composition’ (c.1726–1734) stands out as the only known French tutorial of the period to supply basses akin to the contemporary partimenti used by Italian music teachers to instruct young pupils in the art of extemporaneous composition. Bernier is said to have studied with Caldara—though Corelli is more likely—in Rome, before settling in Paris in 1692. Thus not only do the partimento-like basses included in his ‘Principes de composition’ offer an echo of his studies with these Italian masters, but they may also reflect the Roman beginnings of the pedagogical partimento tradition. The Bernier treatise provides rare testimony of the importance of Corelli’s six opuses in the Italian contrappunto pratico tradition in the period 1690–1730. This article puts Bernier’s ‘Principes’ into context, and then examines his hitherto overlooked basses, their originality, and their pedagogical implications.