GREGORIO X, POPE. – Tedaldo Visconti, born in Piacenza around 1210; he became a canon and professor in his native city; having entered the service of Cardinal Pecorara, a famous diplomat of the period, he gained experience and made useful acquaintances; he resided in Paris while St. Thomas and St. Bonaventure were teaching there, was appointed archdeacon of the diocese of Liège, and papal legate in England. He went to the East with an expedition that failed because of the death of Louis IX. At the death of Clement IV, the Sacred College, assembled in Conclave at Viterbo, was divided by bitter dissensions and, unable to reach any conclusion, finally appointed a commission with the power to decide; perhaps on the advice of St. Bonaventure, Tedaldo was chosen, although he was neither a cardinal nor a priest and was still in the Holy Land (1st week of Sept. 1271). Upon his return he was crowned (23 March 1272) and assumed the name of G. X.
G. X. carried out considerable activity, with the pacification of minds and nations as his objective: he personally visited many Italian cities in order to reconcile the Guelph and Ghibelline factions, but with little success; he compelled the imperial electors to choose a ruler in order to put an end to the great interregnum (on the Pope’s own suggestion, the choice fell upon the modest feudal lord Rudolf of Habsburg, and this too was a move intended to counterbalance French and Angevin intrusiveness); he was tolerant toward the Jews, took a keen interest in Marco Polo’s journey to the East, received the ambassadors of the Tatar and Mongol princes benevolently, established the Apostolic Almonry, and laid down new regulations for the Conclave.
In 1274 he celebrated the Council of Lyons (v.) at which he achieved union with the Greek Church, although it did not last long. On the return journey from Lyons to Rome, G. X met Rudolf of Habsburg at Lausanne and reached an agreement with him concerning the coronation and an expedition to the East; but before reaching his see he died at Arezzo on 10 January 1276. He was buried in the Cathedral, and in the 18th century he was recognized as blessed. The programme of his pontificate reveals great zeal and an uncommon political capacity.
At the age of 42, having been unanimously elected pope on 30 December 1370, he took the name G. XI. He was crowned on 5 January 1371, the last of the seven French popes of Avignon. At the age of 12 he was a canon of Rodez and Paris; at 19 his uncle, Clemente VI, had created him cardinal deacon with the title of S. Maria Nova. As a cardinal, rather than living amid the splendour of the Avignonese court, he preferred to devote himself to study: he went to Perugia, where he studied law under the guidance of Pietro Baldo degli Ubaldi.
As pontiff, he reformed monastic Orders, among them the Fratelli Pescatori; he intervened in the East in defence of pilgrims, conceiving the idea of a Crusade, which, however, was never undertaken. His policy succeeded in bringing peace between Carlo IV and Luigi d'Ugheria and between the duke of Bavaria and the count of Savoy. He tried, in vain, to reconcile France and England, since he understood that only Franco-English peace would make possible the realization of two great designs: the return of the Holy See to Rome and the Crusade; but his action in this regard was opposed by the king of France himself, Carlo V.
Petrarch had already repeatedly expressed his hope for this return, and the Romans themselves had addressed G. heartfelt appeals, accompanied by the vow and prophecy of St. Brigida; but in Italy two great powers opposed the return: the Visconti and Florence. G. tried unsuccessfully to overthrow the Visconti lordship, and against Florence, which viewed with hostility the consolidation on its borders of the Papal State, so effectively advanced by Albornoz, he proclaimed the interdict on 31 March 1376. Before long, many cities that had hitherto remained faithful to the Pontiff began to rebel, joining the Florentine League. G. understood that temporal power in Italy was vanishing if he remained longer in Avignon; St. Caterina da Siena, whom the Florentines had meanwhile sent to the Pontiff as a mediator, overcame his final inward resistance, and on 13 September 1376 G. left Avignon, entering Rome on 17 January 1377, where he was welcomed by the rejoicing population. Death overtook him on 27 March 1378. He was buried in S. Maria Nova, where Pier Paolo Olivieri, commissioned by the Roman Senate, erected a monument to him in 1589.