ADO, Saint. — Archbishop of Vienne in the Dauphiné. Of noble family, he was born at the beginning of the 9th century, apparently in the diocese of Sens. As a youth he was received by Abbot Sigulf, a disciple of Alcuin, into the abbey of Ferrières, where he made his profession. Later, at the request of Abbot Marcard, he transferred to the abbey of Prüm in Lorraine. Finding opposition there from envious persons, he left and went to Rome (where he remained five years), then to Ravenna, and finally to Lyon, where he was given charge of the parish of S. Romano (cf. Lupus of Ferrières, Epist., 122: PL 119, 595). Elected Archbishop of Vienne in 859–60, he governed that see until his death on 16 December 875.
A. is one of the most illustrious prelates of medieval France. Strong and pious, he restored ecclesiastical discipline and regulated divine worship, convening several synods for this purpose, whose acts unfortunately have been lost except for a fragment of that of 870 (Mansi, XVI, 561 sqq.). He vigorously opposed the divorce of Lothair II of Lorraine from Theutberga and maintained frequent correspondence with the popes Nicholas I and Adrian II (cf. MGH, Epist., VI, 766: index, s.V. ADAMO). The Roman Martyrology commemorates him on 16 December.
A. left various historical and hagiographical writings: 1) A Chronicle divided into the six ages of the world, from Adam to the year 869, following Bede and others; but from 814 onwards it is independent. Here A. shows how the various personages of the Old Testament are types of Jesus Christ; regrettably, however, he resorts to historical falsifications to enhance the importance of his own archiepiscopal see. 2) A reworking of the Passio of St Desiderius, bishop of Vienne in the 6th century. 3) The Vita of St Theuderius, founder of a monastery near Vienne in the 6th century. 4) A Libellus de festivitatibus Apostolorum.
But A.’s famous work is his Martyrology, composed at Lyon before 859: a “historical” Martyrology that was of great importance in the Middle Ages and, through Usuard, exerted considerable influence on the Roman Martyrology—an influence, however, that Quentin calls “pernicious.” It is now established that many dates, locations, identifications, and translations that have caused difficulties in the history of the saints, especially in Rome, are nothing more than inventions of A. The same Quentin has demonstrated that the so-called Old Roman Martyrology, the Vetus or Parum Romanum, which A. placed at the head of his major work to support his inventions, is also his composition.
Studies: J. Mabillon, S. Adonis elogium historicum, in Acta SS. Ord. s. Bened., IV, 11, Paris 1680, pp. 262–75, reprinted in PL 123, 9–22; BHL, nos. 82–83 and Suppl. p. 5; L. Duchesne, Fastes épiscopaux de l'ancienne Gaule, I, 2nd ed., Paris 1907, pp. 147–62 (catalogue of the bishops of Vienne), 201, 210; H. Quentin, Le Codex Bezae, à Lyon? Les citations du Nouveau Testament dans le Martyrologe d'Adon, in Rev. Bénéd., 23 (1906), pp. 1–25; id., Les Martyrologes historiques du moyen âge, Paris 1908, pp. 400–681; id., La correction du Martyrologe Roman, in Analecta Bollandiana, 42 (1924), pp. 387–406; G. Morin, Dom Quentin sur les Martyrologes, in Rev. Bénéd., 25 (1908), pp. 232–35; W. Kremers, Ado von Vienne, sein Leben und seine Schriften, Bonn 1911; Martyr. Romanum, 587–88.