de Jubainville, Marie-Henri d'Arbois- (1827–1910), Celtic scholar and linguist, was born 5 December 1827 at Nancy, France, son of Charles-Joseph d'Arbois de Jubainville, judge-auditor of the civil tribunal of Nancy and later advocate to the bar of that district, and his wife Henriette (née de Beaufort de Gellercourt). He went to school at Nancy, where he studied law, becoming bachelor-at-law (13 August 1846); later he went to Paris, where he was granted his licentiate (8 March 1850). He obtained a diploma in archival palaeography at l'École de Chartres on 11 February 1851. From 18 February 1852 until his retirement in March 1880, he was archivist for the département of Aube. During this period he published his Répertoire archéologique du département de l'Aube (1861) and his multi-volume Histoire des ducs et comtes de Champagne (1859–67). He was named chevalier of the Légion d'honneur in April 1856, a correspondent of the Institute of the Légion on 29 December 1867, and a non-resident member of the Comité des travaux hístoriques on 12 October 1868.
His first article in Celtic studies – on the phonetics of the Breton dialect of Vannes – was published (1870) in Revue Celtique, then under the editorship of its founder Henri Gaidoz. In 1881 he travelled to Britain and Ireland to prepare a report on Irish manuscripts on behalf of the department of public instruction in France. He also improved his knowledge of Old Irish and Welsh literature. His particular interest lay in the language of the Old Irish sagas, and as a consequence of his visit to Ireland he published his Essais d'un catalogue de la littérature épique de l'Irlande in 1883. In the same year he published his Études grammaticales sur les langues celtiques. In 1882 he was appointed as the first professor of Celtic studies in the Collège de France – the creation of which chair he had himself proposed. Three years later he became editor of Revue Celtique, in which capacity he remained until his death. His teaching in the Collège de France and his editorship of Revue Celtique did much to advance Celtic studies in France. He was also actively involved in the movement for the revival of the Irish language, and became a member of the Society for the Preservation of the Irish Language in 1899. He was made an officer of the Légion d'honneur (1901), along with many other high accolades and honorarial posts which he received in his native France. He achieved recognition outside France in 1904, when he was awarded an honorary degree by Königsberg university and (in the same year) honorary membership of the RIA. A Mélanges in his honour was published in 1906.
He made the company of several Irish-speaking persons in Paris, including John Millington Synge (qv), who attended his classes in Old Irish in 1898, and to whom he had been introduced by Maud Gonne (qv). De Jubainville's enormously wide interests spanned law, palaeography, history, language, and literature, and he published prolifically in all these fields. His most important publications in Celtic studies were Introduction à l'étude de la littérature celtique (1883); Le cycle mythologie celtique (1884), later translated by R. I. Best (qv) as The Irish mythological cycle and Celtic mythology (1903); L'épopée celtique en Irlande (1892); Éléments de grammaire celtique (1903); and his greatest single contribution, Cours de littérature celtique (1883–1902). Most of his remaining publications were on the Celtic peoples and their religion, in which he developed an increasing interest. He died 26 February 1910 in Paris, and his fellow French celticist, Georges Dottin (qv), truly described him as ‘a renaissance man’ (Revue des Études Anciennes, April–June 1910, p. 6).
He married first (1857) Melanie de Plante-Wildentag (d. 1863), and secondly Charlotte de Pinterville de Cernon, with whom he had a family.