IDACIUS. – Chronicler, born ca. 395 at Lemicia in Galicia (now Jinzo de Lima, in Portugal), died ca. 468. Bishop of Aquae Flaviae (now Chaves in Portugal) from 427, he took part in political struggles against the Suevi invaders and especially in religious conflicts against the Priscillianists; Leo the Great, in fact, placed him alongside St Turibius for the Synod of Galicia (Ep. 15, 17: PL 54, 692), and Turibius himself wrote to him concerning these heretics (ibid., cols. 693-95).
He wrote a Chronicon, continuing that of St Jerome, covering the years from 378 to 460 and of exceptional importance for the period of the invasion and for the history of Galicia under the Suevi. The first part, from 378 to 427, is based on oral traditions and written sources now lost; for the rest, the only sources are his own experience and personal recollections. The work, which has a national character, pays special attention to events in Spain and has the merit of having introduced as a system of dating the Spanish era (v. ERA).