DELISLE, LEOPOLD VICTOR (1826-1910), French bib liophile and historian, was born at Valognes (Manche). At the cole des Chartes, where his career was remarkably brilliant, his valedictory thesis was an Essai sur les revenus publics en Nor mandie au Xlle siecle (1849), and it was to the history of his native province that he devoted his early works. Of these the Etudes sur la condition de la classe agricole et l'etat de l'agricul tare en Normandie an moyen age (1851), condensing an enor mous mass of facts drawn from the local archives, was reprinted in 1905, without change, and remains authoritative. In Nov. 1852 he entered the manuscript department of the Bibliotheque Imperiale (Nationale), of which in 1874 he became the official head in succession to Jules Taschereau. Delisle was responsible for the catalogue of printed books in the library, and under his ad ministration the library was enriched with numerous acquisitions, notably by the purchase of a part of the Ashburnham mss. He was elected member of the Academie des Inscriptions et Belles Let tres in 1859, and became a member of the staff of the Recueil des liistoriens de la France, collaborating in vols. xxii. (1865) and xxiii. (1876) and editing vol. xxiv. (1904), which is valuable for the social history of France in the 13th century. After his retire ment (Feb. 21, 1905) he prepared a catalogue and description of the printed books and mss. in the Musee Conde at Chantilly, left by the duc d'Aumale to the French Institute. Of his other works may be mentioned his Melanges de paleographie et bibliographie (188o) with atlas; Memoire sur les actes d'Innocent III. (1857), and Mernoire sur les operations financieres des Templiers (1889), a collection of documents of the highest value for economic his tory. The 32nd volume of the Histoire litteraire de la France, which was partly his work, is of great importance for the study of 13th and 14th century Latin chronicles. Delisle was un doubtedly the most learned man in Europe with regard to the middle ages; and his knowledge of diplomatics, palaeography and printing was profound. His output of work, in catalogues, etc., was enormous, and his services to the Bibliotheque Nationale in this respect cannot be overestimated. His wife, a daughter of Eugene Burnouf, was for many years his collaborator.
The Bibliographie des travaux de L. Delisle (1902, supplement 1911) , by Paul Lacombe, may be consulted for a full list of his numerous works.