Metropolitan bp. of Mabbug (modern Membij/ancient Hierapolis) (485–519), ascetic theologian, christological polemicist, and sponsor of the Philoxenian NT. Born in Beth Garmai before 450, Philoxenos was educated in Edessa and likely ordained in Antioch under Patr. Peter the Fuller (ca. 470s). With Peter, Philoxenos joined the controversies over the anti-Chalcedonian addition to the Trisagion. Exiled from Antioch under Patr. Calendio (482–484), Philoxenos sojourned among the monasteries of Syria. Supporting the Henotikon, Philoxenos visited Constantinople in 484 to offer Zeno a Miaphysite profession of faith. Upon Peter’s restoration in 485, Philoxenos was named metropolitan of Mabbug. Philoxenos soon established a reputation as a theologian of asceticism (following Evagrius of Pontus) and christology (following Cyril of Alexandria). Writing primarily for monastic audiences, Philoxenos considered the fight against christological error to be a step in the ascetic pursuit of divine knowledge.

By the 490s, Philoxenos emerged as the senior leader of the anti-Chalcedonians in Syria and Mesopotamia, particularly after 498 when the pro-Chalcedonian Flavian was named patr. of Antioch. Philoxenos had little success converting Mabbug to Miaphysite christology. Nevertheless, he used his thirty-year tenure to bolster Miaphysite theology throughout the Roman East and beyond (supporting missionaries in Persia and Nagran).

Philoxenos’s theology was very much centered on the Greek milieu of Antioch and Constantinople. Philoxenos came to mistrust traditional Syriac vocabulary as insufficient for expressing the nuances of Greek christological thought. He sought to bring Syriac theology closer to Greek terminology and established Mabbug as a center for translation. He sponsored a new translation of the NT into Syriac by the auxiliary bp. Polykarpos. Philoxenos himself wrote polemical commentaries on portions of Matthew, Luke, and John. No copies of the Philoxenian version are extant (having been superseded by the later Ḥarqlean translation), but firsthand evidence of the scriptorium survives in three mss. produced in Philoxenos’s own lifetime: London, Brit. Libr. Add. 14,528; 14,534; and 17,126.

Philoxenos’s anti-Chalcedon efforts culminated in 512 when Flavian was ousted in favor of Severus as patr. of Antioch. Philoxenos and his suffragan bishops (including a relation, Philoxenos of Doliche) assisted at Severus’s consecration. Although later opponents vilified Philoxenos and Severus as uncompromising, epistolary evidence reveals that they initially struck a conciliatory tone as they sought to consolidate Miaphysite control of the clergy in Syria and Anatolia.

In 519, Justin I exiled Philoxenos. In his final years, Philoxenos continued writing to monastic communities, encouraging them to persist in ascesis and Miaphysite christology. Philoxenos died in 523 under house arrest. Later traditions that he was executed are difficult to substantiate.

Philoxenos’s reputation grew after his death. Several 6th- and 7th-cent. mss. survive citing his works alongside Cyril and Severus. Philoxenos’s cult was strong in Ṭur ʿAbdin where his relics were translated to a church dedicated to him in Midyat and to the Monastery of Mor Gabriel. In the 13th cent. Eli of Qarṭmin composed a valuable life of Philoxenos.

Although Philoxenos’s ascetic Discourses circulated widely in their entirety, the majority of his corpus was preserved only in the catena of polemical handbooks, stripping his christological polemics of their ascetic context. Considering his entire corpus, Philoxenos was no mere polemicist. He played the many roles of late antique bp., monastic leader, prolific theologian, biblical commentator, and would-be imperial counsellor.

Liturgical commemorations for Philoxenos are attested for 10 Dec., 18 Feb., 1 and 2 April, and 16 and 18 Aug.