Juan de Valdes played a pivotal role in the febrile atmosphere of sixteenth-century Italian religious debate. Fleeing his native Spain after the publication in 1529 of a book condemned by the Spanish Inquisition, he settled in Rome as a political agent of the emperor Charles V and then in Naples, where he was at the centre of a remarkable circle of literary and spiritual men and women involved in the religious crisis of those years, including Peter Martyr Vermigli, Marcantonio Flaminio, Bernardino Ochino and Giulia Gonzaga. Although his death in 1541 marked the end of this group, Valdes...