La chanson d'Yde et Olive, an early fourteenth-century epic poem from the Picard region, exemplifies the medieval custom of text renewal that seeks to adapt pagan materials to fit Christian doctrine. Largely based on the plot of the Ovidian fable Iphis and Ianthe from The Metamorphoses, its main character Yde undergoes a metaphorical transformation from a woman into a man. Moreover, much like the Ovide moralisé, a Christianized adaptation of the Latin original, Yde et Olive's message can be understood as a Christian parable for the purging of the sinful soul. To set up the poem's didactic message, the poet carefully infuses the story with contemporary social concerns, such as the theme of incest and gender disruption, both potentially offensive forces to the medieval social structure. In the backdrop of these threats to society, the heroine's overcoming of her struggles becomes all the more meaningful, leading to a clear moral message to the reader. While being a hybrid in genre and structure, the poem shows many borrowings from Christian hagiography, especially from the later, more romance-influenced versions of the Vitae of female transvestite saints. In these narratives, the heroine's spiritual development is typically portrayed in terms of "becoming male," which can also be understood as an erasure of sexual difference to approach God in a Neoplatonic sense. Moreover, the development of Yde's own hybrid state leading to the climax of revealing her new sex exemplifies medieval literary criticism, elaborating on the central theme of uncovering truth by exposing the hidden gem beneath the rough surface.