Ammonius , a disciple of Pambo, and one of the most celebrated of the monks of Nitria. Being of unusual stature, he and his brothers Dioscorus, Eusebius, and Euthymius were called the Tall Brothers (Soz. Hist. viii. 12). Ammonius himself was distinguished by the epithet παρωής (Niceph. Hist. xi. 37), in consequence of having cut off one of his ears to escape being made a bishop (Pall. Hist. Laus. 12). In his youth he accompanied St. Athanasius to Rome (Socr. Hist. iv. 23; Pall. 12). He was a learned man, and could repeat, it is said, the O. and N. T. by heart, as well as passages from Origen and other Fathers (Pall. 12). He was banished to Diocaesarea in the persecution under Valens ( ib. 117). After being for some time high in favour with Theophilus of Alexandria, he and his brothers were accused by him of Origenism. Sozomen (viii. 12) and Nicephorus (xiii. 10) ascribe the accusation to personal animosity on the part of Theophilus. Socrates (vi. 7) explains the accusation as an attempt to divert from himself the odium which he had incurred as an Origenist. Jerome considers the accusation merited ( Ep. ad Alex. ). Driven from Egypt, the brothers took refuge first in Palestine (Niceph. xiii. 11) and afterwards at Constantinople, where they were well received by Chrysostom (viii. 13). There they were protected also by the favour of the Empress Eudoxia (Soz. viii. 13), and even satisfied Epiphanius of Salamis, who came to Constantinople at the instigation of Theophilus to convict them of heresy (viii. 15). At the synod "ad Quercum," held on the arrival of Theophilus, they were persuaded to submit to him, Ammonius being ill at the time. He died shortly afterwards. Perhaps this Ammonius is the author of the Institutiones Asceticae , of which 22 chapters are extant (Lambec. Biblioth. Vindob. iv. 155).