The elder, of Sinai (d. c. 430), was one of the many disciples and fervent defenders of St. John Chrysostom
Nilus, Saint (Greek: Neilos) the elder, of Sinai (d. c. 430), was one of the many disciples and fervent defenders of St. John Chrysostom. We know him first as a layman, married, with two sons. At this time he was an officer at the Court of Constantinople, and is said to have been one of the Prxtorian Prefects, who, according to Diocletian and Constantine's arrangement, were the chief functionaries and heads of all other governors for the four main divisions of the empire. Their authority, however, had already begun to decline by the end of the fourth century.
While St. John Chrysostom was patriarch, before his first exile (398-403), he directed Nilus in the study of Scripture and in works of piety (Nikephoros Kallistos, "Hist. Eccl.", XIV, 53, 54). About the year 390 (Tillemont, "Memoires", XIV, 190-91) or perhaps 404 (Leo Allatius, "De Nilis", 11-14), Nilus left his wife and one son and took the other, Theodulos, with him to Mount Sinai to be a monk. They lived here till about the year 410 (Tillemont, ib., p. 405) when the Saracens, invading the monastery, took Theodulos prisoner. The Saracens intended to sacrifice him to their gods, but eventually sold him as a slave, so that he came into the possession of the Bishop of Eleusa in Palestine. The Bishop received Theodulos among his clergy and made him door-keeper of the church. Meanwhile Nilus, having left his monastery to find his son, at last met him at Eleusa. The bishop then ordained them both priests and allowed them to return to Sinai. The mother and the other son had also embraced the religious life in Egypt. St. Nilus was certainly alive till the year 430. It is uncertain how soon after that he died. Some writers believe him to have lived till 451 (Leo Allatius, op. cit., 8-14). The Byzantine Menology for his feast (November 12) supposes this. On the other hand, none of his works mentions the Council of Ephesus (431) and he seems to know only the beginning of the Nestorian troubles; so we have no evidence of his life later than about 430.
From his monastery at Sinai Nilus was a well known person throughout the Eastern Church; by his writings and correspondence he played an important part in the history of his time. He was known as a theologian, Biblical scholar and ascetic writer, so people of all kinds, from the emperor down, wrote to consult him. His numerous works, including a multitude of letters, consist of denunciations of heresy paganism, abuses of discipline and crimes, of rules ant principles of asceticism, especially maxims about the religious life. He warns and threatens people in high places, abbots and bishops, governors and princes, even the emperor himself, without fear. He kept up a correspondence with Gains, a leader of the Goths, endeavoring to convert him from Arianism (Book I of his letters, nos. 70, 79, 114, 115, 116, 205, 206, 286); he denounced vigorously the persecution of St. John Chrysostom both to the Emperor Arcadius (ib., II, 265; III, 279) and to his courtiers (I, 309; III, 199).
Nilus must be counted as one of the leading ascetic writers of the fifth century. His feast is kept on November 12 in the Byzantine Calendar; he is commemorated also in the Roman martyrology on the same date. The Armenians remember him, with other Egyptian fathers, on the Thursday after the third Sunday of their Advent (Nilles, "Kalendarium Manuale", Innsbruck, 1897, II, 624).
The writings of St. Nilus of Sinai were first edited by Possinus (Paris, 1639); in 1673 Suarez published a supplement at Rome; his letters were collected by Possinus (Paris, 1657), a larger collection was made by Leo Allatius (Rome, 1668). All these editions are used in P.G., LXXIX. The works are divided by Fessler-Jungmann into four classes: (I) Works about virtues and vices in general:—"Peristeria" (P.G., LXXIX, 811-968), a treatise in three parts addressed to a monk Agathios; "On Prayer" (Greek: peri proseuches, ib., 1165-1200); "Of the eight spirits of wickedness" (peri ton th`preumaton tes ponerias, ib., 1145-64); "Of the vice opposed to virtues" (peri tes antizugous ton areton kakias, ib., 1140-44); "Of various bad thoughts" (peri diapsoron poneron logismon, ib., 1200-1234); "On the word of the Gospel of Luke", xxii, 36 (ib., 1263-1280). (2) "Works about the monastic life":—Concerning the slaughter of monks on Mount Sinai, in seven parts, telling the story of the author's life at Sinai, the invasion of the Saracens, captivity of his son, etc. (ib., 590-694); Concerning Albianos, a Nitrian monk whose life is held up as an example (ib., 695-712); "Of Asceticism" (Logos asketikos about the monastic ideal, ib., 719-810); "Of voluntary poverty" (peri aktemosunes, ib., 968-1060); "Of the superiority of monks" (ib., 1061-1094); "To Eulogios the monk" (ib., 1093-1140). (3) "Admonitions" (Gnomai) or "Chapters" (kepsalaia) about 200 precepts drawn up in short maxims (ib., 1239-62). These are probably made by his disciples from his discourses. (4) "Letters":—Possinus published 355, Allatius 1061 letters, divided into four books (P.G., LXXIX, 81-585). Many are not complete, several overlap, or are not really letters but excerpts from Nilus' works; some are spurious. Fessler-Jungmann divides them into classes, as dogmatic, exegetical, moral, and ascetic. Certain works wrongly attributed to Nilus are named in Fessler-Jungmann, pp. 125-6.