NILO the Younger, Saint. — Also called of Rosano, where he was born ca. 910. Of illustrious birth, N. received a very careful education; soon he entered as a simple cleric in the service of the Cathedral. From a girl of very modest condition, whom he married, he had a daughter.
Wishing to withdraw from the world, he went to the region of Mercurio, where for many years he led a solitary and penitential life in the grotto of St. Michael. Because of the continual Saracen incursions, he first moved to the mountains north of Rossano, organizing around the oratory of St. Adrian a first community, which he then led to Vallecure near Montecassino, and thence to Serperi, near Gaeta. He made frequent pilgrimages to the tombs of the Apostles, also with the purpose of procuring parchments and bringing back books. In 998 he went there to intercede on behalf of the unfortunate antipope Filagato (John XVI), his centenarian. In 1004 he left Serperi and, by divine impulse, arrived in the Tusculanum, where he received from Count Gregory the territory of Grottaferrata for his last and most lasting foundation; but in that same year, on the evening of 25 September, he died.
Besides being the most representative figure of Italo-Greek monasticism in the 10th century, St. N., who also knew Latin, was an expert calligrapher and the author of that particular system of shorthand called Italo-Greek, of which his manuscripts, together with those of his immediate disciples, formed the first nucleus of the Cryptense Library, providing a fine example. He was also a hymnographer, and there have been preserved a Greek office in honor of St. Benedict, sung during one of his visits to Montecassino, and a hymn for St. Nilo of Sinai. The biographer expressly mentions some of his letters: to the judges of Bisignano, to the notary of the emir of Palermo, to Abbot Leo of St. Alessio on the Aventine, and to the antipope Filagato. His feast is set in the Roman Martyrology and in the Italo-Greek Synaxaria on 26 September.