PIER DELLE VIGNE (de Vineis). — Celebrated minister of Frederick II, born, it seems, in Capua around 1190, if it is true that he was about sixty years old at the time of his political disgrace. From his letters, it appears that his family was of modest means, but his father, Angelo, was already a judge in Capua. According to a statement by the astrologer Guido Bonatti, it seems that P. studied law in Bologna, but from his letters it only emerges that he studied under Giacomo of Amalfi, bishop of Patti and archbishop of Capua.
According to Henry of Isernia, P. was presented to Frederick by Bernardo, archbishop of Palermo, which may have occurred in December 1220 when the Emperor was in Capua. In 1225, P. appears with the title "judge of the great court"; after 1243 he was imperial protonotary and logothete. From 1238 to 1247 he is listed as "familiaris domini," i.e., intimate counsellor of the Emperor. In 1230 he had taken part in the negotiations for the Peace of San Germano and accompanied Frederick II to Ceprano for the final agreements. The following year he took part in drafting the Constitutions of Melfi: an ancient tradition attributes the main merit to him, but today it is thought that P. was only a collaborator of Giacomo of Amalfi, to whom indeed Gregory IX’s reproaches for those Constitutions are directed. In 1231 he was repeatedly ambassador of Frederick II to the Pope, though alongside a high ecclesiastical dignitary who directed the mission while P. handled the actual business. In 1234 P. was in England for the negotiations for Frederick’s marriage to Isabella of Plantagenet and on 22 November 1234 gave the ring to the bride at Westminster as the Emperor’s procurator. In 1235 he was with Frederick in Germany; he was sent to Italy to negotiate with the Ghibelline communes and took an important part in the Congress of Piacenza. A trusted confidant of the Emperor, in 1237 he went with Hermann von Salza to the Pope, then to Mantua with Taddeo of Sessa to negotiate with the papal legates. After the battle of Cortenuova (1237), he followed Frederick II into Piedmont, then under Brescia and to Padua, where, on the occasion of Gregory IX’s new excommunication of Frederick, he spoke to the people in defence of the Emperor.
Later he took part in the negotiations with the Sacred College and with Innocent IV: in 1244 in Rome with Taddeo of Sessa he swore the terms of the agreement that Frederick II then failed to ratify. He then remained in the Emperor’s retinue in Foggia, Verona, Turin, and from there went as ambassador to Louis IX of France to obtain his mediation in the conflict with the Pope. In 1247 he was again in Turin with Frederick II for an agreement attempted through the count of Savoy; he then followed the Emperor to the siege of Parma.
In January 1249 he was with Frederick II in Cremona when he suddenly lost imperial favour. The reason is unknown. It was thought that he was suspected or accused of complicity with Innocent IV, or that the policy he pursued finally provoked Frederick’s anger, or that courtiers and rivals accused him of conspiring against the Emperor. Referring to P., Frederick II says: "Pravae suggestionis et scandali multiformis Petri videlicet, Somnios alterius, proditoris, qui ut haberet loculos vel impetret, equitatis virgum vertebat in colubrum." But the charge of corruption and venality was perhaps only the pretext to strike at the former favourite. Frederick accused him of having tried to poison him: the well-informed English chronicler Matthew Paris repeats this accusation; Dante, however, portrays P. as the victim of calumnies by envious courtiers. Arrested in Cremona in
Pian delle Vigne (de Vineis) — P. d. V. in a chair. Miniature from the codex Ottobonianus lat. 1101, f. 1 (14th century) containing the epistles of P. d. V. — Vatican Library.
February 1249, transferred to Borgo San Donnino, P. was then led in chains behind the Emperor during his move to San Miniato, where he was tried and condemned to blinding. A Piacenza chronicler has him dying in prison as a result of the barbarous execution; Matthew Paris and Dante (Inf., XIII) record the rumour of suicide (April 1249).
It seems that P. had a wife and children; the accounts of his literary activity still require careful critical examination: in his epistolary, his own letters must be distinguished from those not his; there are political speeches, a political treatise, a Latin poem on the months of the year, a satire in monorhymed quatrains against the clergy, and some political compositions in the vernacular.