Education
University of Paris.
archbishop cardinal Catholic priest
University of Paris.
He was then appointed Vicar-General of the diocese of Sens and, in 1721, accompanied Cardinal de Rohan to Rome as his conclavist, to support the candidacy of Cardinal Conti (Innocent XIII), from whom he had obtained a promise to bestow the purple on the French minister Guillaume Dubois. He remained at Rome as French chargé d"affaires, with the appointment in commendam of abbot of Trois-Fontaines to support him (1739–1753), until Benedict XIII, with whom he was on cordial terms of intimacy and very influential, consecrated him Archbishop of Embrun (26 June 1724). On 22 February 1739, Guérin de Tencin was created cardinal, of the titulus of Saints
Nereus and Achilleus.
He remained at Rome as French ambassador until 1742, when he took possession of the archiepiscopal see of Lyon, to which he had succeeded on 19 November 1740. Louis XV appointed him minister of state in September 1742, though he held no portfolio, and Commander of the Order of Saint-Esprit.
He was overzealous in the persecution of the Jansenists, and, at the provincial synod which he held at Embrun from 16 August to 28 September 1727, he suspended Jean Soanen, Bishop of Senez, a prelate eighty years of age, who had appealed against the Bulletin Unigenitus. After the death of André-Hercule Cardinal de Fleury, the prime minister to whom he owed much of his political advancement, his influence began to decrease.