abbot. Born of a Greek family settled in Calabria, he became an official of the treasury. Before he was thirty, he suffered the loss both of his mistress and of their daughter. He became a monk in a Greek monastery nearby, lived in several abbeys as hermit or cenobite, and became abbot of St Adrian's, near San Demetrio Corone. During most of his life both Saracens from Sicily and mercenary soldiers were a repeated threat to peace.
Nilus became reputed for his austerity and holiness as well as his knowledge of Greek and Latin literature and for his composition of hymns. He seems to have believed that the numbers of the saved were extremely small; on the other hand, he did not easily grant monastic status to powerful laymen: ‘Your baptismal promises are quite sufficient without your taking monastic vows: these are not required for repentance, but only a sincere determination to change your way of life.’
In 981 he fled with his community of 60 monks from the Saracen armies, travelling north to Monte Cassino, where they were warmly welcomed by the successor of Benedict. They were given hospitality and sung the Greek Liturgy in the abbey church until they moved to the empty monastery of Vallelucio, where they lived for 15 years. From there they moved on to Serperi (near Gaeta), where the Emperor Otto III visited them in 999 and was astounded by their primitive conditions of life. He offered to rebuild the monastery but Nilus refused, accepting instead a purse of money.
In 1004 he visited Grottaferrata (near Rome), where he was assured in a vision that this would be his community's permanent home. Before the building was completed he died, but he is reckoned as this monastery's founder. For nearly 1,000 years this Byzantine-rite abbey has flourished as a place of holiness and learning, formerly devoted to the production of manuscript books, but nowadays to their conservation by the most modern scientific techniques. Feast: 26 September.
AA.SS. Sept. VII (1867), 262–319; Lives by A. Rochi (1904) and G. Giovanelli (1966); see also D. Attwater, Saints of the East (1963), pp. 118–24; Bibl. SS., ix. 995–1008.