The “new” Italianate poetry written in Spain by Boscán and Garcilaso de la Vega is inextricably linked, as critics have noted, to their translation of Castiglione's Book of the Courtier. This essay explores the specific impact of Castiglione's book in Garcilaso's “Second Eclogue,” a poem that incorporates the idea of courtiership as ethical training and of the courtier as pedagogue that Castiglione introduces in the last segment of his work. The relationship between courtiership and ethics is critical for understanding Garcilaso's transformation of the Ariostan model (Orlando XLVI.89) that inspires the depiction of the relation between Boscán and the Duke of Alba in the poem. Meanwhile the image of the courtier as pedagogue determines the ideological implications of the contrast that Garcilaso establishes throughout the Eclogue between the duke and the shepherd Albanio.