He was born 11 December 1724 in the castle of Baillet in the town of Bayers, then in the ancient Province of Angoumois, now part of the Department of Charente.

[2] As a young man, Montmorency-Laval studied at the Sorbonne University in Paris, where he obtained a licentiate in canon law.

He was also appointed in 1786 Grand Almoner of France,[2] and on 30 March 1789 Pope Pius VI created him a cardinal.

[1] During the French Revolution Montmorency-Laval left France and lived in exile in the Kingdom of Denmark–Norway, settling in the town of Altona, now a part of Germany.

His body was initially buried at the local church of St. Joseph of the "Greater Freedom" (German: Großer Freiheit).