René-Louis de Ficquelmont (1589–1654), abbé de Mouzon, was commendatory abbot of Mouzon, Élan and Belval, and from 1624 to 1641 Louis XIII of France's diplomatic representative in the Principality of Liège.
He was clothed as a monk, and promoted the Benedictine reform of the Congregation of St. Vanne in the monasteries entrusted to him.
[2] In 1629 he convinced Richelieu of the desirability that France should guarantee Liège's neutrality in the face of incursions by both Dutch forces and the Army of Flanders.
[3] Mouzon spent lavishly in the French interest, receiving 67,750 livres between March 1635 and November 1639, but failed to convince the Liégeois to accept French intervention after the murder of Sébastien de La Ruelle in 1637.
[5] In 1641 he was forced out of Liège by the resurgent Chiroux party, opposed to French intervention in the principality.