Thanks to critics such as Ros Ballaster, Paul Salzman, Mary Helen McMurran and Leah Orr, we are now aware that the history of early English prose fiction in the seventeenth century should be seen in a transnational context, and that it is intricately linked with the translation of French, Spanish and Italian contemporary fiction. Translation provided a space for experimentation and opened up English fiction to continental trends. The contiguity between translation and creation is manifest in the juxtaposition of Aphra Behn’s Agnes de Castro, a translation of a French histoire galante by Jean-Baptiste Brilhac, with two of her original stories, The Fair Jilt and Oroonoko, in Three Histories (1688). Ros Ballaster has argued that Behn “built her career in prose on translation from the French,” but this compilation, although perhaps an editorial, rather than authorial, choice, shows that in Behn’s career translating and writing new fiction are intimately related. With Agnes de Castro, a work still sometimes mistaken for an original work, Behn capitalizes on the new vogue for French fiction in translation, but her choice of a sentimental Portuguese story, a form of historical fiction which is a hapax in her short career, was a bold move and showed her experimenting with a genre that had just become fashionable. Intriguingly, her translation was published the very same year as a rival translation by Peter Belon, a commercial translator who specialized in fiction from the French. This article interrogates the meaning of this competition for French fiction and looks at the potential connections between the two translations. As will be apparent, Behn’s treatment of the most sentimental features of the story reflects her particular mediation of the novella of sentiment. Moreover, Agnes de Castro leads us to reconsider the engagement of Behn with commercial translation.