Pietro Pileo di Prata (or da Prata) (c.1330–1400) was an Italian bishop and cardinal.Eubel, Hierarchia catholica I, p. 23, no. 2. He was a significant diplomat and go-between in the affairs of his times, and was nicknamed the "cardinal with three hats", which he obtained successively from Urban VI, Clement VII, and Boniface IX.

Early life Pileo was the son of Count Bianchino and Iselgarda da Carrara, the sister of Jacopino da Carrara. Hortis, pp. 22-24. He was born in the Castello di Prata in the diocese of Concordia or, perhaps, in Padua itself.

He was patronized by the family of Francesco il Vecchio da Carrara, lord of Padua. He was a Canon of the cathedral of Padua in 1350 at the age of twenty,Dondi attributes the appointment to the patronage of the Carraresi: and held the dignity of Archpriest from 1356,Hortis, p. 23. though he was only in minor orders, when he was appointed bishop of Treviso by Pope Clement VI on 1 June 1358.* Eubel, p. 480. As bishop-elect, he initially had a Vicar General, Giorgio Torti of Pavia, and he is recorded as bishop as late as 28 June 1359. He did not enter Treviso, however, due to the hostility of the clergy and citizens and the hostility of the Venetians against Francesco di Carrara, whose family were patrons of the bishop.

Bishop of Padua Pileo was appointed bishop of Padua by Pope Innocent VI on 12 June 1359.Eubel, p. 386. As bishop, he summoned and presided over a diocesan synod on 8 March 1360.Dondi dall'Orologio VIII, pp. 106–107. At exactly the same time, he was involved in his capacity as Grand Chancellor of the University of Padua, in mediating a dispute between the Law Faculty and the Arts Faculty, as to whether there should be one university or two. On 20 March 1360, he issued his decision, that there should be two institutions, but that the Rector of the Arts should swear to obey the statutes of the Law Faculty.There had originally been one university, which the law professors came to dominate to the extent that all members of the university where obliged to obey their statutes and their Rector. The professors of Medicine and of the arts set up their own organization with their own Rector, and were agitating to be considered a separate university independent of the Law faculty. Dondi dall'Orologio VIII, p. 107. In 1361, he modified the statutes of the cathedral Chapter, allowing younger Canons who were studying at the university to do so without penalty for their absence from their cathedral duties.Dondi dall'Orologio VIII, p. 108. Bishop Pileo also obtained from Pope Urban V a chair in theology for the University of Padua, only the third such chair to be established, after Paris and Bologna.Dondi dall'Orologio VIII, p. 109. Others put it that the University was entitled to issue doctoral degrees in theology. In 1394, he founded the Collegio Pratense in Padua, for the benefit of scholars studying at the University of Padua, and provided for the institution in his Testament of 1399.Dondi dall'Orologio VIII, p. 112. Malmignati says that the number of scholars was set at 20, and that they were to be drawn from Padua, Venice, and Treviso.

Archbishop of Ravenna On 23 January 1370, he was named archbishop of Ravenna by Pope Urban V. When he was named a cardinal in 1378, he relinquished the episcopal throne, but continued on as Administrator of the diocese.Eubel, pp. 23, no. 2; 415. In 1372, Pope Gregory XI summoned Pileo to Avignon, and sent the archbishop along with the Bishop of Carpentras, Guillaume l'Estrange,Eubel, p. 168. as his nuncios to King Charles V of France. They were instructed to obtain a truce, and to bring representatives of France, England, and Navarre together to compose their differences. A conference took place in Bruxelles in 1374, with Archbishop Pileo and the Bishop of Carpentras serving as papal nuncios. Louis of Anjou and Philip of Burgundy took part. Pope Gregory wrote a letter to the King of France, threatening ecclesiastical censures against those who should reject the proposals of the nuncios. The most they could obtain was a truce in 1375, which was extended to 1377. The sticking point was Calais, which the English absolutely refused to surrender, and therefore the war continued.

In 1376, Archbishop Pileo was drawn into the expansionist military adventures of Barnabò Visconti of Milan, who threatened Tuscany as well as territories belonging to the papacy, including Bologna and the Patrimony of S. Peter. The archbishop was ordered by Pope Gregory to support his Cardinal Legate in Bologna and the Marchese d'Este with the sum of 500 gold florins charged against the archbishop's income as bishop. The raising of the required sums brought the archbishop a bad reputation as a despoiler of church property. At the same time, a Ghibelline rebellion in Ravenna cut the archbishop off from his source of income.

In 1377, an opportunity arose which might have allowed Pope Gregory to repay Archbishop Pileo for his expenses in the papal diplomatic service, and to compensate him for his losses in Ravenna. The diocese of Tournai had become available, and Pileo was proposed for the post. But he was not eager to leave an archbishopric for a bishopric, unless he could hold Ravenna in commendam along with Tournai. The pope was willing to name him a patriarch along with Tournai, but at the moment no patriarchate was available, and the pope was set against holding two bishoprics at the same time. All he could promise Pileo, as he wrote on 4 January 1378 in his letter of refusal, was that the subject would be revisited at the next patriarchal vacancy. As it happened, Pope Gregory died on 27 March 1378.

Cardinal Pileo di Prato was named a cardinal by Urban VI on 18 September 1378, and assigned the church of Santa Prassede as his titular church.Eubel, pp. 23, no. 2; 45. His first duty was to write a letter to the King of France, explaining the election of Urban, and arguing for its canonical validity. Writing from Venice on 15 December 1378, he also posted a lengthy letter to Count Louis of Flanders.

Urban VI had sent him as a legate to Germany and Hungary, a journey made all the more critical since the Emperor Charles IV had died on 29 November 1378, and his successor Wenceslaus had sent representatives to Rome. Wenceslaus was promising obedience to Urban VI, and was seeking an imperial coronation. Pileo followed Wenceslaus to Mainz, Cologne, and Aix-la-Chapelle. The electors of Mainz and Cologne were important for the election of a Holy Roman Emperor. Pileo took the opportunity to lobby bishops on behalf of Urban VI's legitimacy, but Leopold of Austria and Wenceslaus of Brabant were pressing the new King of the Romans to summon a general council to deal with the growing schism, a move which would have called into question exactly what Pileo was promoting. He is said to have counselled Wenceslaus to resist the demands.

In 1381, Pileo was sent along with several German nobles to arrange a marriage between King Wenceslaus' sister, Anne of Bohemia, and King Richard II of England, who were married in January 1382. He is accused of having used his legatine powers to the maximum while he was in England, lifting excommunications and cancelling vows of pilgrimage, receiving generous gifts for his services. He was greedy for money.Baluze, p. 1361. Dondi, pp. 71–74, quotes the evidence, but rejects some of it because the author did not accept Urban VI, and Walsingham because he must have been motivated by some private passion: "Forse questo quadro è tropo caricato, forse l' autore era condotto scrivendolo da qualche privata passione, ma certo è che egli prova la Legazione di Pilleo in Inghilterra ad evidenza, e che prova anche non sempre li Ministri costituire il Principe, ma che alcune volte questi si addattano o al volere, ò al sistema pratico del Sovrano e che 'Regis ad exemplum totus componisur Orbis'." The Cardinal was back in Italy by 4 September 1382, where he visited Prata and manumitted all of his serfs, both there and elsewhere.

Naples In October 1383, Pope Urban determined on a visit to the Kingdom of Naples. He took with him six cardinals, among them Pileo di Prata, and the papal court. The pope was extremely dissatisfied with the situation following the French invasion by Louis of Anjou, a supporter of the Avignon Pope Clement VII, and the passive defense offered by King Charles of Durazzo. He was equally dissatisfied with Charles' casual reception of his overlord into the Kingdom of Naples, but continued on to the city. The Neapolitans hated Urban, since many were still loyal to their original allegiance to Pope Clement VII in Avignon, whom Queen Joanna I had recognized as the true pope. They were hostile to Charles of Durazzo, who had murdered Queen Joanna and had frustrated Louis of Anjou's expedition. The pope's real purpose was to enhance his own family's fortune, in particular those of his nephew, Francesco Butillo, who had been cheated by Charles of Durazzo out of his share of the spoils of the destruction of the expedition of Louis of Anjou. A favorable opinion of the Neapolitans was solicited by the marriage of two of the pope's nieces to Neapolitan noblemen, but on Christmas Eve his nephew Francesco reversed it all by breaking into a convent and raping a noble Neapolitan nun. The pope quashed the legal proceedings against Francesco, and helped him to escape to his fief at Nocera. Theoderic was a witness to many of the events, but never an impartial one. He hated Urban VI and many of his own colleagues in the Roman Curia. In June 1384, Pope Urban was forced to leave Naples and seek refuge with his nephew at Nocera. In August, however, the cardinals who were at Nocera and many of the curiales fled to Naples.Theoderic, p. 69.

On 17 December 1384, Pope Urban held a consistory at Nocera, and Cardinal Pileo was promoted from Cardinal Priest of S. Prassede to the post of suburbicarian Bishop of Tusculum (Frascati).His predecessor as Bishop of Tusculum, Cardinal Guillaume de Chanac, had died on 30 December 1383. Several prelates were offered a cardinal's hat, but declined: Archbishop Fridericus de Saarwerden of Cologne, Archbishop Adolfus de Naasau of Mainz, Archbishop Cuno de Falkenstein of Trier, Bishop Arnoldus de Horn of Liege, Bishop Wenceslaus de Silesia-Liegnitz of Bratislava, and Father Petrus de Rosenberg of Prague. Nine prelates accepted.Theoderic (who was present), pp. 80-82. Eubel, pp. 24-25, 39.

Meanwhile, Cardinal Bartolomeo Mezzavacca, who was residing in Naples, set in motion an inquiry, led by the curialist Bartolomeo of Piacenza, to examine the question of deposing a pope if he were judged insane. He also consulted masters of theology and several Doctores in utroque iure, as well as King Charles and Queen Margarita.Theoderic, pp. 77-78. Urban VI heard of the consultations, and on 11 January 1385, he ordered the arrest of those cardinals within his reach: Joannes de Amelia, Gentilis de Sangro, Adam de Eston, Ludovicus Donati, Bartholomaeus de Cucurno, and Martinus de Judice. All except for Eston were killed at Genoa in December 1386 on orders of Urban VITheoderic I. 42, pp. 77-79. Eubel, pp. 23-24. Creighton, pp. 80-81.

After the torture of the six cardinals began in the dungeons of the castle of Nocera, to which Theoderic of Nyem was a witness, five of the cardinals at liberty, led by Pileo di Prata, wrote an open letter to the clergy of Rome,Stephanus Baluzius [Étienne Baluze], Vitae Paparum Avinionensium Volume 2 (Paris: apud Franciscum Muguet 1693) columns 983-988. detailing Urban's cruelties and furies, announcing that Urban VI was a heretic, and that they were withdrawing from his Obedience. Four of the five cardinals were deposed from their cardinalates,The four cardinals were: Luca Gentile, Poncello Orsini, Bartolommeo Mezzavacca, and Landolfo