DUCHESNE, LOUIS-MARIE-OLIVIER. - French prelate, distinguished archaeologist, historical-critic, and writer, b. at St-Servan (Ille-et-Vilaine) on 13 Sept. 1843, d. at Rome on 21 Apr. 1922. He completed his studies brilliantly at the college of St-Servan, the minor seminary of St-Méen, the St-Charles school of St-Brieuc, and the major seminary of the same city. Bishop David, his ordinary, sent him to Rome to earn a doctorate in theology at the Collegio Romano (1864-66); there he met Giovanni B. De Rossi and formed a friendship with the future monsignor M. d'Hulst. Ordained priest at Christmas 1867, Bishop David assigned him to teaching, then permitted him to continue his classical studies in Paris at the *École des Carmes* (1870-71); in 1872 he enrolled at the *École des Hautes-Études*, where he attended courses in archaeology, epigraphy, and Greek and Latin philology (1872). When the French *École archéologique* was established in Rome on 5 March 1873, Du Chesne was among its first candidates. In February of the following year, he and his colleague Carlo Bayet were entrusted with a scientific mission to Epirus and Thessaly, which enabled them, among other things, to visit the libraries of the monasteries of Mount Athos and Patmos; the outcome was highly successful.
In 1876, Du Chesne, together with Massimo Collignon, undertook another archaeological exploration in southwestern Asia Minor, interrupted by the political events of that year. On 10 March 1877, he defended two theses—one in Latin and one in French—for his doctorate in Paris. The French thesis on the *Liber Pontificalis* was so successful that Minister W.-H. Waddington immediately offered the new doctor a university chair, but Du Chesne declined the flattering invitation to accept instead the chair of ancient Church history, created for him at the nascent *Institut catholique* in Paris. He felt called to “serve the Church through its history, studied conscientiously and presented frankly” (P. Peeters, *L'oeuvre des Bollandistes*, Brussels 1942, p. 116), and in fact he served it admirably with his studies, which contributed in a primary way to the renewal of ecclesiastical historiography promoted by Leo XIII with the letter *Saepenumero* of 18 Aug. 1883.
The rigorous method Du Chesne introduced into his teaching and studies alarmed the epigones of the then-current historical “dominatism,” and the young professor, too biting in speech and writing and merciless in exposing the presumptuous ignorance of his opponents, encountered endless troubles and insults. Fortunately, in Paris he was protected by Monsignor d'Hulst and in Rome by Giovanni B. De Rossi. In 1887, after leaving the *Institut catholique*, he became a professor at the *École des Hautes-Études*, and the following year a member of the *Académie des inscriptions*. From 1895 until his death he resided in Rome as director of the French School at the Palazzo Farnese. In 1896 he took an active part in the campaign for the union of the Anglican Church with Rome; in 1900 he organized and directed the second Congress of Christian Archaeology. From December 1899 to 1922 he was president of the Society of Lovers of Christian Archaeology. On 18 May of the same year he was enrolled among the apostolic protonotaries; on 18 Dec. 1901 among the consultors of the Sacred Congregation of Indulgences and Relics; on 28 Nov. 1902 among the members of the historical-liturgical commission established that day at the Sacred Congregation of Rites. Finally, on 26 May 1910 he was elected to the Academy of France. In that same year, Du Chesne became the target of an unseemly campaign of accusations and insults, to which he reacted with extreme firmness, fortified by the fact that his *Histoire ancienne de l'Église*, against which the fury of the libelists raged, bore the imprimatur of the Master of the Sacred Palace and that he had personally presented each of the three published volumes to the Holy Father. The condemnation of his *Histoire* (22 Jan. 1912: *AAS*, 6 [1912], pp. 56-57) was a severe trial for Du Chesne; he accepted it and submitted to it without delay: “Faithful child of the Church,” he declared on 5 Feb. to Cardinal Della Volpe, “I must submit to its decisions. I therefore come to declare to Your Excellency that I respectfully bow before the decree of the Sacred Congregation of the Index regarding my book” (*L'Osservatore Romano*, 6 Feb.; “laudabiliter se subiecti”: *AAS*, loc. cit., p. 103). This sorrow and the fluctuating events of the war of 1914-18, to which Du Chesne was deeply sensitive, soon overcame his strong constitution. With the accession of Pius XI, he hoped to obtain rehabilitation for his work, suitably revised, but death came to him before that hope could be realized; during his brief illness he was assisted by Fr. Genocchi, to whom he requested the last sacraments, and Pius XI, who had detained him at length a few days earlier on the 10th, sent him his blessing. His remains rest in the cemetery of St-Servan. Despite all the accusations leveled against him, Du Chesne was a man of good heart and a priest of irreproachable life, sustained by sincere and active faith; yet his natural causticity did him harm.
Endowed with a very fine intuition and an exceptionally penetrating intelligence, Du Chesne possessed a capacity for work that was extraordinary: proof of this is the 429 items in his bibliography, though not complete, collected and arranged chronologically from 1875 by H. Leclercq (*DACL*, IV, II, cols. 2711-35). Du Chesne confined himself to ancient Church history and that of the early Middle Ages; he was an archaeologist and historian, but above all a critic and philologist.
The *Liber Pontificalis*, the *Martyrologium Hieronymianum*, and the *Liber censuum* were the cornerstones on which he built the best part of his scholarly output. Of the first and third he provided critical editions, and for the second he collaborated on the diplomatic edition and left a manuscript commentary for the first eight months, from which Fr. H. Delehaeye drew profit, citing II. Most of his articles are nothing more than investigations into particular points that needed to be studied in order to proceed with the edition of the aforementioned sources or that were only touched upon in his major works.
I. THE *LIBER PONTIFICALIS* AND STUDIES INSPIRED BY II
D. established its various recensions and classified 110 manuscripts for his doctoral thesis (*Etude sur le Liber Pontificalis*, Paris 1877), then published its critical edition (*Le Liber Pontificalis, texte, introduction et commentaire*, 2 vols., ibid. 1886 and 1892, based on 150 manuscripts), which has remained unsurpassed both for the text he established and for the archaeological, hagiographical, and historical commentary that accompanies II. Even Th. Mommsen, though in his 1898 edition (*MGH: Gestorum Pontificum Romanorum*, I) he improved the critical apparatus and disagreed with D. on secondary matters, made this open acknowledgment regarding the manuscript classification: «Hanc meam editionem Duchesniarum non reformat, sed comprobat et confirmat» (p. cx). He polemicized with G. Waitz and R. A. Lipsius regarding the classification of manuscripts and the date of the *Lib. Pont.* (*La date et les recensions du Lib. Pont.*, in *Revue des questions hist.*, 26 [1879], pp. 493-530; *Le premier Lib. Pont.*, ibid., 29 [1881], pp. 246-83; *Un mot sur le Lib. Pont.*, in *Mélanges d'arch. et d'hist.*, 6 [1886], pp. 275-83). The following articles are preliminary studies for the commentary on the *Lib. Pont.* or developments of issues touched upon in the introduction or commentary: *Le Lib. Pont. en Gaule au VIe siècle* (in *Mélanges d'arch. et d'hist.*, 2 [1882], pp. 3-15); *La succession de Félix IV* (ibid., 3 [1883], pp. 239-66); *L'histoire géographique au VIIIe siècle* (ibid., 4 [1884], pp. 237-73); *Vigile et Pélage. Etude sur l'histoire de l'Eglise romaine au milieu du VIe siècle* (in *Revue des questions hist.*, 36 [1884], pp. 369-440); *Serge III et Jean XI* (in *Mélanges d'arch. et d'hist.*, 33 [1913], pp. 25-64); *Le Lib. Pont. aux mains des guibertistes et des pierlèonistes* (ibid., 38 [1920], pp. 165-93).With *Les circonscriptions de Rome pendant le moyen âge* (in *Revue des questions hist.*, 24 [1878], pp. 217-25), D. began an interesting and extensive investigation into Roman topography, which he later resumed under the title: *Notes sur la topographie de Rome au moyen âge*, published in 14 installments in the aforementioned *Mélanges* from 1886 to 1915. To these *Notes* are added: *Les légendes de l'Alta Semita* (ibid., 36 [1916-17], pp. 27-56) and *Le sanctuaire de St-Laurent* (ibid., 39 [1921], pp. 3-24).
Another work closely related to the study of the *Lib. Pont.* is the one titled: *Les premiers temps de l'Etat pontifical* (Paris 1898, 3rd ed., ibid. 1911, Italian trans. I, Turin 1947), which describes with concise sobriety the rise and establishment of papal power from 754 to 1073.
II. THE *MARTYROLOGIUM HIERONYMIANUM*
In his first year of teaching at the *Institut catholique* (1877), D. took this important hagiographical source as the subject of his study and practical exercises. The conclusions he reached were such that D. Rossi wished to have him as a collaborator for the edition he had in mind to publish (cf. *Roma sotterranea*, III, Rome 1877, p. XXII). The diplomatic edition reproducing in four columns the full text of the principal manuscripts appears in the *Acta SS. Novembris* (II, 1, Brussels 1894: *Martyrologium Hieronymianum ad fidem codicum adiectis prolegomenis*). The greater part of the introduction is by D.; it deals with the origins, sources, and restoration of the text, discreetly proposing a manuscript classification that contrasted with that of his mentor, a classification later adopted by Quentin. He had already addressed this topic in the article: *Les sources du martyrologe hiéronymien* (in *Mélanges d'arch. et d'hist.*, 5 [1855], pp. 120-60), to which De Rossi prefixed a brief introduction (*ibid.*, pp. 115-19). D. clarified his contribution to the edition and insisted on his conclusions in a dignified response to the harsh criticism and quibbles of Br. Krusch: *A propos du martyr. hiér.* (in *Analecta Bohleniana*, 17 [1894], pp. 421-47); *Un dernier mot sur le martyr. hiér.* (ibid., 20 [1901], pp. 241-45). In 1920, he also indicated how to restore the text: *Sur le martyrologe dit de St Jérôme*, in *Miscellanea Giovanniana* (Rome 1920, pp. 221-26).III. THE *LIBER CENSUUM*
The edition of this important source for the history of the Roman Church had been begun by P. Fabre, who published only one fascicle in 1889. In memory of his friend and drawing on the material he had collected, D. completed it in 1910 (*Le Liber censum de l'Eglise romaine*, I, Paris 1889-1910; II, *Le Liber censum romain sous Grégoire IX et Innocent IV avec ses suppléments*, ibid. 1905). The article: *L'auteur des «Mirabilia»* (in *Mélanges d'arch. et d'hist.*, 24 [1904], pp. 479-89), in which D. identifies its author as Benedetto Canonico, is closely related to this edition.IV. THE EPISCOPAL *FASTI* AND RELATED STUDIES
From 1883 to 1915, D. studied the origins of Christianity in Gaul and the ancient episcopal catalogues of the sees of the same region. After a series of preliminary articles, the principal of which are: *Les origines du christianisme en Gaule* (in *Annales de philosophie chrétienne*, 8 [1883], pp. 1-15); *Mémoire sur l'origine des diocèses épiscopaux de l'ancienne Gaule* (in *Mémoires de la Soc. des antiquaires de France*, 50 [1890], pp. 337-416); *St Martial de Limoges* (in *Annales du Midi*, 4 [1892], pp. 289-330); *La légende de Ste Marie-Madeleine* (*ibid.*, 5 [1893], pp. 1-33), D. presented the results of his extensive epigraphical and historical investigations in the three volumes of the *Fastes épiscopaux de l'ancienne Gaule* (I, Paris 1894; 2nd ed. ibid. 1907; II, ibid. 1900; 2nd ed. ibid. 1910; III, ibid. 1915). A bold work conducted with impeccable scientific rigor, in which historical data are freed from all legendary dross. His demonstration of the absolute lack of apostolic origins for various Frankish episcopal sees provoked lively controversy. Closely connected to the research for his *Fastes* are the articles: *St Barnabé* (in *Mélanges J.-B. De Rossi*, Rome 1892); *Les anciens recueils de légendes apostoliques* (in *Compte-rendu du 3e Congrès scientifique international catholique tenu à Bruxelles du 3 au 8 sept. 1894*, Brussels 1895, pp. 67-79); *St Jacques en Gaule* (in *Annales du Midi*, 12 [1900], pp. 145-80).