AILERANO (Aileranus, Aieranus, Aieranus, Eerianus), called the WISE, saint. — Little is known of his life. He was a monk at Clonard (v.) and, apparently, from 650 onward he headed that school. Bellesheim considers him one of the “most representative doctors” of Ireland in the seventh century. He died in 664 or 665. Oengus (v.) commemorated him on 29 December.
There survives from him an Interpretatio mystica Progenitorum Christi, also interesting for the knowledge it provides of the books that made up the monastic libraries of Ireland (St. Jerome, Origen, Arnobius, Flone, Flavius Josephus, etc.). A. sets forth the traditional interpretation; from his manner of expression, he shows that he was ignorant of Hebrew.
The treatise, supplemented by the Moralis explanatio eorumdem nominum, was published, from a manuscript of S. Gallo, by the Franciscan Patrizio Flemine, at Louvain (1667), together with the works of St. Columbanus. It was subsequently included in the Biblioteca maxima Patrum of Lyon in 1677 (XII, pp. 37–41), and reproduced in PL 80, 327–42. That edition, however, is incomplete. Charles Mac-Donnel, in Proceedings of the Royal Irish Academy (7 [1857–61], pp. 369–71), published the missing portion from a manuscript in the Imperial Library of Vienna (Cod. theol., 119), which contains an unpublished work by Sedulius Scotus (v.), the Collectaneum in Matthaeum.
The poem called Kanon Evangeliorum (that is, In X canones Eusebi, seu concordantiam quatuor Evangelistarum), formerly included among the poetic compositions of Alcuin (PL 101, 729), must be considered A.’s work, as De Bruyne demonstrated, relying chiefly on cod. Barberin. 587.
Colgan (Acta Sanctorum Hiberniae, Louvain 1645, p. 140) attributes to A. three lives of saints (now lost): of Brigid of Kildare, Patrick, and Fechin of Fore.
Eugenio O’Curry then (in Irish Ecclesiastical Record, 1 [1864], pp. 63–64) published, with an English translation, a prayer in Gaelic attributed to A. by the Yellow Book of Lecan, which has preserved its text.
A work entitled Rethorica Aierani (sic), which must have been a grammatical work of his, was found, in the eleventh century, in the monastic library of S. Floriano, near Linz.