San Pietro martire e la «voce del sangue». Alcuni sermoni duecenteschi.

The essay analyses the evolution of preaching on saint Peter martyr in the 13th cen- tury through sermons based on the biblical theme “Vox sanguinis” (Gen 4:10). Texts written by Friars Preachers such as Thomas Agni de Lentini, Albert the Great and others reveal various uses of saint Peter martyr in the fight against heresy and his sig- nificance in the creation of the Order’s identity. The sources exhibit the development of omiletic narration. The emphasis on parallelism between Abel and Christ is soon replaced by a greater emphasis on hagiographical topics, on Peter’s role as inquisitor and his interpretation as the pioneer of a new era of martyrs. In appendix the edition of an unpublished sermon kept in the State Library of Cremona.