PIERIUS, pi-er'i-us: Presbyter of Alexandria. According to an excerpt from the" Christian History" of Philippus Sidetes by H. Dodwell, Dissertatio in Irenœum (Oxford, 1689), it appears that Pierius was the head of the catechetical school at Alexandria, the successor of Dionysius, and predecessor of Theognostus [c. 265 A.D.]. Photius also names Pierius as master of the school and teacher of Pamphilus. Eusebius (Hist. eccl., VII., xxxii. 26, 27, 30, Eng. transl. in NPNF, 1 ser., i. 321-322, cf. note 42) names Achillas, later bishop, as conductor of the school at that time, and if this is correct, the two might have been jointly at the head. At any rate his character, according to Eusebius, of ascetic, philosopher, exegete, and preacher, would present him as amply qualified. Sidetes also states, on the authority of a lawyer, Theodore, that Pierius and his brother Isidore were martyrs and had a very large church at Alexandria, which is also reported by Photius. Jerome (De vir. ill., lxxvi.; also his second Epist. Ad Pammachium, Eng. transl. in ANF, vi. 157) states that, after the persecution of Decius, Pierius lived at Rome. The work (Byblion) of Pierius to which Photius refers (Codex cxix.) consisted of twelve treatises or addresses, of which also Sidetes makes mention. One of these was an extemporaneous first Easter sermon, mentioned by Photius. The address upon the martyrdom of his pupil Pamphilus which contains exegetical elements is to be distinguished from the Biblion, and the representation of Jerome that he was the author of a commentary on I Corinthians is not substantiated. Pierius was a follower of Origen, was indeed called "the younger Origen," and his writings were studied with those of Origen.