As a writer he is chiefly known as the reputed author of a collection of martyrologies which cover the reigns of Sapor II., Yazdegerd I.
In Celtic and English martyrologies (November 25) there is also commemorated St Catherine Audley (c. 1400), a recluse of Ledbury, Hereford, who was reputed for piety and clairvoyance.
Gregory of Nyssa's untrustworthy panegyric represents him as having wrought miracles of a very startling description; but nothing related by him comes near the astounding narratives given in the Martyrologies, or even in the Breviarium Romanum, in connexion with his name.
In the West, the name of St Nicholas appears in the 9th century martyrologies, and churches dedicated to him are to be found at the beginning of the 11th century.
The earliest traditions appear to imply that he died a natural death (Eusebius, Jerome, and even Isidore of Seville); but the Martyrologies claim him as a martyr, though they do not agree as to the manner of his martyrdom.