Catholic Encyclopedia
St. Porphyrius was bishop of Gaza, and died in 420.
For All the Saints
Pious account of the life of St. Porphyrius, who was a monk at Skete and then a hermit before he was made bishop. Also called Porphyry.
Mark the Deacon: The Life of Saint Porphyry, Bisho
Mark the Deacon was associated with St. Porphyrius from 397 onwards. Long account of the saint's life and holy death.