French statesman, born at Grenoble on the 11th of October 1611, of an old family of Dauphiné. Early trained for diplomacy, his remarkable abilities attracted the notice of Cardinal Mazarin, who sent him as secretary of the French embassy to the congress of Münster, and, in 1642, on a mission to the pope. In 1646 he became secretary to the queen regent; in 1653 obtained high office in the king’s household; and in 1654 was ambassador extraordinary at the election of Pope Alexander VII. He was instrumental in forming the league of the Rhine, by which Austria was cut off from the Spanish Netherlands, and, as minister of state, was associated with Mazarin in the Peace of the Pyrenees (1659), which secured the marriage of Louis XIV. to the infanta Marie Thérèse. At the cardinal’s dying request he was appointed his successor in foreign affairs, and, for the next ten years, continued to direct French foreign policy. Among his most important diplomatic successes were the treaty of Breda (1667), the treaty of Aix-la-Chapelle (1668) and the sale of Dunkirk. He died in Paris on the 1st of September 1671, leaving memoirs. He was a man of pleasure, but his natural indolence gave place to an unflagging energy when the occasion demanded it; and, in an age of great ministers, his consummate statesmanship placed him in the front rank.
See Ulysse Chevalier, Lettres inédites de Hugues de Lionne … précédées d’une notice historique sur la famille de Lionne (Valence, 1879); J. Valfrey, La diplomatie française au XVIIIe siècle: Hugues de Lionne, ses ambassadeurs (2 vols., Paris, 1877–1881). For further works see Rochas, Biogr. du Dauphiné (Paris, 1860), tome ii. p. 87.
