Pope Gregory X

Pope Gregory X (Latin: Gregorius X; c. 1210 – 10 January 1276), born Teobaldo Visconti, was head of the Catholic Church and ruler of the Papal States from 1 September 1271 to his death and was a member of the Third Order of St. Francis. He was elected at the conclusion of a papal election that ran from 1268 to 1271, the longest papal election in the history of the Catholic Church.

He convened the Second Council of Lyon and also made new regulations in regards to the papal conclave. Gregory was beatified by Pope Clement XI in 1713 after the confirmation of his cultus.

Gregory's regulations on the conduct of the conclave, though briefly annulled by Adrian V and John XXI, remained standard practice until the 20th century. Gregory's rules were dispensed in certain extraordinary circumstances, offering greater latitude in regulating an upcoming conclave, such as by Pope Pius VI in 1798, in consideration of the occupation of Rome by the French, and by Pope Pius IX in 1878, fearing a potential Vatican invasion could prevent or dominate a papal election.

Teobaldo Visconti, a member of the Visconti family, was born in Piacenza around 1210.

It is said that he began his career by attaching himself to the household of the Cistercian Cardinal Giacomo di Pecorari, Bishop of Palestrina (1231–1244), who was also from Piacenza. He was attracted by the reputation of holiness which the Cardinal enjoyed; he had been elected abbot of the monastery of Trois-Fontaines in Champagne. Teobaldo became the Cardinal's Oeconomus or Majordomo, and was therefore in constant attendance. The Cardinal was Legate of Pope Gregory IX in Tuscany in 1235, in Lombardy in 1236–1237, and in Provence, France and Germany in 1239–1241. It was probably during the assignment in Provence that Teobaldo became known to important French clergy and laity. He was already Canon of the Basilica of S. Antonino in Piacenza when he returned to Piacenza on business of the Cardinal in 1239.

He then returned to the Cardinal, whose new assignment in France was actually to preach a crusade against Frederick II, the Hohenstaufen Emperor, who was again at war with Pope Gregory IX. Early in 1239, the Pope had again excommunicated the Emperor. Each had demanded an Ecumenical Council to settle their differences. The Pope was willing, but he planned that the council would meet under his auspices and in his territory. He would also bring to Rome all of the enemies of Frederick Hohenstaufen. It was at this point in 1240 that Teobaldo also became a Canon of the Cathedral of Lyons, at the request of the Canons made to Cardinal Giacomo de Pecorari when a vacancy in their number occurred. Pope Gregory's ecumenical council never took place, and he died on 22 August 1241.

The search for a successor to Gregory IX took more than two months. The new Pope, Celestine IV, who was old and ill, survived his election by only 17 days, dying on 10 November 1241. The second electoral assembly of 1241 did not take place for some time, however. The cardinals who were in Rome at the pope's death, having endured considerable mistreatment during the Vacancy of 22 August 1241 to 25 October 1241, which they did not want to endure again, scattered immediately. Only a half-dozen of the 12 cardinals remained in the city. It was not until June 1243 that all the Cardinals, assembled at Anagni and not in Rome, elected Cardinal Sinibaldo Fieschi of Genoa as Pope Innocent IV. In 1243, when the Bishop of Piacenza died, Innocent IV offered the position to Archdeacon Teobaldo, who declined, preferring to follow in the company of Cardinal Giacomo. Cardinal Giacomo, however, died in Rome on 25 June 1244.

Upon the death of his patron and spiritual model, Teobaldo decided not to remain any longer in the Curia, planning to travel to Paris, where he would study theology. When he reached Lyons, however, he was received by the Archbishop-elect, Philippe, who asked him to be the dominus and magister of the household. Teobaldo initially refused, but the Archbishop insisted and finally Teobaldo accepted the position.