ADO (d. 874)  , archbishop of Vienne in Lotharingia, belonged to a famous Frankish house, and spent much of his middle life in Italy . He held his archiepiscopal see from 859 till his death on the 16th of December 894 . Several of his letters are extant and reveal their writer as an energetic man of wide sympathies and considerable influence . Ado's principal works are a Martyrologium (printed inter al. in Migne, Patrolog. lat. cxxiii. pp . 18i-420; append. pp . 419-436), and chronicle, Chronicon sive Breviarium chronicorum de sex mundi aetatibus de Adamo usque ad ann . 869 (in Migne, cxxiii. pp . 20-138, and Pertz, Monumenta Germ. ii. pp . 315-323, &c.) . Ado's chronicle is based on that of Bede, with which he combines extracts from the ordinary sources, forming the whole into a consecutive narrative founded on the conception of the unity of the Roman empire, which he traces in the succession of the emperors, Charlemagne and his heirs following immediately after Constantine and Irene . " It is, " says Wattenbach, " history from the point of view of authority and preconceived opinion, which exclude any independent judgment of events . " Ado wrote also a book on the miracles (Miracula) of St Bernard, archbishop of Vienne (9th century), published in the Bollandist Acta Sanctorum; a life or Martyrium of St Desiderius, bishop of Vienne (d .

6o8), written about 87o and published in Migne, cxxiii. pp . 435-442; and a life of St Theudericus,

abbot of Vienne (563), published in Mabillon, Acta Sanct. i. pp . 678-681, Migne, cxxiii. pp . 443-450, and revised in Bollandist Acta Sanct . 2gth Oct. xii. pp . 840-843 . See W . Wattenbach, Deutschlands Geschichtsquellen, vol. i . (Stuttgart and Berlin, 1904) .