AMMONIO, saint. — Descendant of a wealthy family of Alexandria, he was a hermit and the principal founder of the monastic colonies of the Nitrian Desert in Egypt. After 18 years of marriage, spent in perfect chastity, he withdrew (between 320 and 330) into the desert of Nitria, according to Palladius (Historia lausiaca, chap. 18) and Sozomen (Hist. eccl., I, 14), in order to live there in solitude. Attracted by the fame of his virtues, many disciples gathered there, and thus the celebrated centers of monastic life in the Nitrian Desert came into being. Esteemed and visited by St. Anthony the Abbot, he died before 385.
In the Greek Church his feast is celebrated on 4 October; he does not appear in the Roman Martyrology.
BIBL.: Acta SS. Octobris, II, Anversa 1768, pp. 413–20; Miracula, in Historia monachorum in Aegypto, ed. E. Preuschen, Palladius und Rufinus, Giessen 1897. Giuseppe Löw