Recent investigation into Joan Boscán’s 1534 Castilian translation of Baldassar Castiglione’s Libro del cortegiano has focused on how Charles V’s Spanish courtiers appropriated Castiglione’s lessons in order to affirm their own status as the elite nobility of their society. These studies, however, overlook the wider European context of international politics, where Charles and his courtiers constantly faced foreign leaders and diplomats to whom they wished to prove that a cultural equality, if not superiority, had indeed accompanied their emperor’s political dominance. In Boscán’s translation, it is possible to note a desire to produce a Spanish book which will replace its Italian counterpart as an elegant source of humanist conceptions of language, history, and rhetoric, already well adapted to a monarchical-imperial ideology. In fact, soon after the publication of this translation, Charles himself demonstrated his own sprezzatura in a speech, steeped in the humanist tradition, given to the European political community.