Guy of Boulogne (1313[1] – 25 November 1373) was a statesman and a churchman, serving the Avignon Papacy for 33 years. He participated in the papal conclaves of 1352, 1362 and 1370, and was the Subdean of the Sacred College of Cardinals. His diplomatic postings were extensive. American historian Kenneth Setton called him "one of the commanding figures of his day, and the letters of Petrarch abound with references to him".
Guy was the third son of Count Robert VII of Auvergne, and his family was well-connected to the greatest houses in France and the Empire. His sister Matilda married Count Amadeus III of Geneva, making Guy uncle of four successive counts of Geneva and of antipope Clement VII. The daughter, Joan, of Guy's eldest brother, Count William XII of Auvergne, married John, Duke of Normandy, later King of France, who thus called Guy his "uncle[-in-law]". On 11 October 1340, Pope Benedict XII approved Guy's election as Archbishop of Lyon, but he did hold it long, surrendering it to become cardinal-priest tituli S. Caeciliae, of Santa Cecilia in Trastevere, on 20 September 1342.
On 22 April 1346, Guy and Cardinal Elias Talleyrand witnessed the pact between King John of Bohemia, his son, the future Emperor Charles IV, and Pope Clement VI. In 1348–50, Guy travelled extensively in Hungary and Lombardy as Clement's legate, his job being to negotiate peace between the former kingdom and the Kingdom of Naples. The two kingdoms had been at war since the murder of the Hungarian prince Andrew, Duke of Calabria, husband of the Neapolitan queen, Joan I, in 1345. He had returned to Avignon by 7 June 1350.[2] Later that year he was made Cardinal-bishop of Porto and Santa Rufina.
In 1351, Cola di Rienzi, from his prison in Prague, wrote a letter to Guy requesting his assistance in obtaining his freedom and leading a crusade. On 6 April 1354 at Guînes, he witnessed the signing by representatives of France and England of a preliminary accord for ending the Hundred Years' War. Between 1359 and 1361 he was in Spain on another lengthy legation, and he took a leading role in negotiating peace between Charles V of France and Charles II of Navarre in 1366. In September 1362, after the death of Pope Innocent VI, the College of Cardinals was divided into two factions, one supporting Guy of Boulogne and the other Elias Talleyrand for pope. In the end a compromise candidate was elected Pope Urban V.
Guy was papal legate in Italy during 1368–69, and was briefly joined by his nephew, the future Clement VII. The two witnessed an imperial diploma of Charles IV at Lucca on 28 February 1369. In Lucca Guy established his headquarters while he served as "lieutenant [lit. place-holder] and general vicar" for the Empire "in the regions [lit. parts] of Italy", having been appointed "by our Caesarean [i.e., imperial] majesty" Charles IV.[3]
On 21 December 1370, Guy gave a eulogy, prepared in a single day, at the funeral of Urban V in the church of Notre-Dame-des-Doms in Avignon. On 30 December, Cardinal Pierre Roger de Beaufort, a nephew of Clement VI, was elected to succeed Urban. On 4 January, Guy ordained him a priest and on the next day crowned him Pope Gregory XI. In 1372–73 Guy undertook his final legation, his second to Spain, to try to make peace between Charles II of Navarre and Henry II of Castile. He died in Spain, at Lleida on 25 November 1373. "There were those who said that he died of poison which was administered to him by the treachery [arte] of Charles [II], King of Navarre".[4]