fully developed his theological views toward the end of his life including during a brief retirement before his death, possibly before the sect fully emerged. Pneumatomachian doctrine was embraced by Eleusius and Marathonius, the latter a major protagonist, and it gained traction in Constantinople, Thrace, Bithynia, and the Hellespont. Under the Emperor Julian, 361 to 363 A.D., who personally rejected Christianity in favor of Neoplatonic paganism, and who sought to return the Roman Empire to its original religious eclecticism, the Pneumatomachi had enough power to declare their independence from both Arians and orthodox. Pneumatomachi beliefs were distinct from, but in some regards reminiscent of, Arianism. Church commentators assert that they denied the divinity of the Holy Spirit, and regarded the substance of Jesus Christ as being of "similar substance" (homoiousios) but not of the "same essence" (homoousios) as that of God the Father. The Macedonians supported the Homoiousian creeds of Antioch and Seleucia and condemned the Homoian creeds of Ariminum and Constantinople, and they called new synods to gain support for their views and condemn their opponents. The Pneumatomachi were denounced in 374 by Pope Damasus I. In 381 A.D., the Pneumatomachian concept that the Holy Spirit was a creation of the Son, and a servant of the Father and the Son, prompted the First Council of Constantinople (also termed the Second Ecumenical Council) to add, “And in the Holy Spirit, the Lord, the Giver of Life, Who proceedeth from the Father, Who with the Father and the Son is equally worshipped and glorified, Who spake by the Prophets,” into the Nicene Creed. As a result of the Second Ecumenical Council, homoousios has become the accepted definition of Orthodox Christianity. Thereafter, the Macedonians were suppressed by the emperor Theodosius I. Three prominent 4th-century saints, Athanasius of Alexandria, Basil of Caesarea, and Basil’s younger brother Gregory of Nyssa, wrote polemics against Macedonianism (Letters to Serapion, On the Holy Spirit, and On the Holy Spirit respectively). Notable Pneumatomachi Macedonius, bishop of Constantinople (342–346 and 351–360)<ref>Socrates Scholasticus. Church History, book 2, chapters 16, 27, 38 & 42</ref> Marathonius, bishop of Nicomedia (c. 351–?) Eleusius, bishop of Cyzicus (c. 351–360)Socrates Scholasticus. Church History, book 2, chapters 38, 42 & 45 Sophronius, bishop of Pompeiopolis (?–360) Eustathius, bishop of Sebastia Sabinus, bishop of Heraclea References Bibliography Haykin, Michael, The Spirit of God: The Exegesis of 1 and 2 Corinthians in the Pneumatomachian Controversy of the