CARNESECCHI, PIETRO. — Heretic, born in Florence on 24 December 1508, beheaded in Rome on 1 October 1567. The son of a noble Florentine merchant and a connoisseur of Greek and Latin literature, he soon won the esteem of the Medici, especially of Cardinal Giulio, who, having become Pope Clement VII, summoned him to Rome as his secretary and provided him with rich ecclesiastical benefices. In a letter of recommendation to Charles V (27 June 1531), he describes him as «summa fide et singulari modestia vir, quem cum suis meritis et deditissimo animo in me, tum virtute et nobilitate ita amo ut plus non possem».
In 1533, alongside Clement VII, he took part in the meeting at Marseille. In Naples, Giulia Gonzaga, whom he esteemed and loved, brought him into contact with Juan de Valdés, Bernardino Ochino, Pietro Martire Vermigli, and other more or less overt supporters of reform in Italy (1536–40). In 1541 he was in Viterbo, where a circle of “spirituali” was forming around the English cardinal Reginald Pole; while remaining within the Church, it was approaching Lutheranism with regard to justification by faith alone. The apostasy of Ochino and Vermigli (1542) alerted the ecclesiastical authorities to the danger of these currents. Nevertheless, C., who was in contact with foreign and native heretics, succeeded in concealing his convictions and was acquitted by the Roman Inquisition for lack of evidence (1546). He then went to France as the guest of Catherine de’ Medici, his patroness and friend. He went to Venice in 1552, increasingly displaying his sympathy for reform. Paul IV summoned him to Rome (1557), but C. refused to appear and was condemned in absentia (6 April 1558). Upon the death of Paul IV, he reappeared in Rome, had his case re-examined, and—by telling, as Pius V would later assert, “a mountain of lies”—obtained the annulment of the previous condemnation (June 1560). Suspicion nevertheless remained, and C.’s conduct was certainly not such as to dispel II. Pius V had his trial resumed. C. was then staying with Cosimo de’ Medici, who, at the Pope’s request, handed him over (July 1566). The trial lasted a year; and instead of confessing and abjuring, trusting in the protection of Cosimo and Catherine de’ Medici, C. obstinately persisted in defending himself. As the evidence against him became increasingly clear, he was finally condemned on 21 September 1567; then, on 1 October 1567, he was beheaded and subsequently burned.