[10] As Bishop of Châlons he was present among the Peers of France in the Lit de Justice of 15 January 1536 [1537], against the Emperor Charles V.[11] Bishop de Lenoncourt was sent as Ambassador to the Emperor by Francis I, in the matter of the Duchy of Guelders which was a fief of the Holy Roman Empire, but which was in alliance with the French, thanks to a secret treaty of October 1534.

[19] In January 1552 Cardinal de Lenoncourt convoked a meeting of the Estates-General of Metz, but his actions appeared to the citizens to be an effort to concentrate all the power in the city in his own hands.

[20] He was instrumental in overthrowing the republic which had existed under Charles V in favor of the French, manipulating the elections for the Council by naming candidates and choosing the Maître-Échevin (President) himself.

Cardinal Robert lost everything for which he had been working, and went so far as to seek the aid of the Emperor in trying to eject the French garrison from Metz.

In 1556 the citizens of Metz petitioned the King of France for relief from their bishop, but Lenoncourt, who had been in Rome for the second Conclave of 1555,[22] had already been transferred to Embrun.

Lenoncourt was named Archbishop of Embrun by King Henri II of France, the appointment being approved by Pope Paul IV (Carafa) in Consistory on 23 March 1556.

Philippe Munier, Titular Bishop of Philadelphia[26] In 1557 the Cardinal appointed his nephew, Jean de Lenoncourt, Abbot of Essômes, to represent him at a meeting of the Estates of Burgundy.

[27] He was succeeded by his nephew Philippe, who made his solemn entry into Auxerre on 8 December 1560, the splendid details of which were recorded and witnessed by a notary.

[29] His spiritual functions as archbishop were carried out by his suffragan and perpetual vicar, Pierre de Bisqueriis, titular bishop of Nicopolis.

[30] On 3 July 1560, the archbishop, bishop, provost, canons and other clergy of the diocese of Arles were accused by the citizens of Arles in the Parliament of Provence of failing, despite more than sufficient revenues assigned for the purpose, to provide preachers for the churches in the diocese on Sundays, Feast Days, Advent and Lent and other major occasions.

[31] While the new archbishop had only received his bulls in February, he and his clergy were put on notice that the people were unhappy with the quality of service being provided.