He is venerated as a saint in the Eastern Orthodox[note 1] and Catholic churches, and his feast day is celebrated on September 26 in both the Byzantine calendar and the Roman Martyrology.

[5] At the time Calabria was under the Byzantine rule and was Koine Greek in language, culture, and spiritual and liturgical tradition.

However, after a while, he realized that he was viewed as a local authority, and hearing that there was talk of making him bishop, Nilus fled to Capua, where he stayed for fifteen years.

Basil, he maintained cordial relations with the Benedictines at Monte Cassino, where he spent some time, as well as at the Alexius monastery in Rome.

[4] Nilus's main legacy is the foundation in 1004 of the famous Greek Catholic monastery at Grottaferrata,[note 2] near Frascati, on what was believed to be the site where Cicero had owned a villa and written his Quaestiones tusculanae.