Destined for the Church from an early age, he completed the necessary studies for this vocation with success. In 1717, while still very young, he was appointed to the Abbey of Saint Romain de Blaye. In 1722 he was made Abbot of Beauport and then nominated as Prior first at Lanville and then at Bonne-Nouvelle.
He then became the vicar general of the Archbishop of Rouen until, on 27 January 1729 after the resignation of Cardinal de Gevres, he was appointed as Archbishop of Bourges. On 7 August 1729 he was installed in this position by the Archbishop of Rouen assisted by the Bishops of Laon and of Beauvais.
In April 1732 he was designated Prior of La Charite sur Loire and, on 29 September 1738, elected as Co-adjutor of Cardinal Henri Oswald de La Tour d'Auvergne, at the famous Abbey of Cluny. On 2 February 1742 he was received as Commander of the Order of the Holy Spirit. Due to his reputation he was chosen as one of the presidents of the Assembly of French clergy which was held the following April.
He then asked the king for the favour of working directly with him in the preparation of this assembly rather than having to go through his ministers, and this request was granted. In 1745 King Louis XV made him ambassador for the French Court to Pope Benedict XIV, replacing the Abb‚ de Canillac.
In 1746 Christophe de Beaumont de Repaire was appointed Archbishop of Paris, even though Monseigneur de La Rochefoucauld had been considered the favourite but his absence abroad cost him this important post. In April 1747 the Cardinal de La Tour d'Auvergne died, and Monseigneur de La Rochefoucauld succeeded him as the head of the Abbey at Cluny which he reconstructed according to new plans. He presided over the general chapters of 1750, 1753 and 1756. In 1747 he
was also elevated "to the purple" and became a cardinal. In December 1747 he was recalled to Paris and replaced in Rome by the Duc de Nivernais.
In 1755, after the death of the Bishop of Mirepoix, the King indicated his personal preference for the Cardinal de La Rochefoucauld as controller for the list of benefices. His virtues and great piety
were responsible for him being named "Grand Aumonier de France", a position which, however, he was not able to fill as he died on the 29th April 1757 in Paris.
He was a gentle person, noble, uncomplicated, a true gentleman, but he had the fault of being a little weak. In his life he showed great dignity; he stood out by his decent straight behaviour and was
attached as sincerely to the Church as he had been to France. He wrote several works, including "Synod Regulations from 1738 to 1744", and "Prayer book of the diocese of Bourges". In 1741 he was also the author of a new breviary.
 

Source: Leo van de Pas