(Gr. = “fighters against the Spirit”). A fourth-century group which denied the deity of the Holy Spirit. Anticipated by the “Tropici” answered by Athanasius in his letters to Serapion of Thmuis, they came to the fore in 373 when Eustathius* of Sebaste became their leader after breaking his friendship with Basil of Caesarea. They were condemned by Damasus of Rome (374), and their doctrines were attacked by the Cappadocian Fathers and Didymus the Blind of Alexandria. The more moderate among them accepted the consubstantiality of the Son, but the more radical (led by Eustathius) regarded both Son and Spirit as “like in substance” or “like in all things” to the Father. Formally anathematized with other heresies at the Council of Constantinople in 381, the sect disappeared after 383, victims of the Theodosian antiheresy laws. Some early writers (Socrates, Sozomen, Jerome, Rufinus) regarded Macedonius of Constantinople as their founder, and they are sometimes called Macedonians; but Macedonius disappeared from sight after his deposition by the Arian Council of Constantinople in 360, and there is no known connection with the later sect, unless he worked out the theories in retirement. Possibly his followers amalgamated with the Pneumatomachi. Occasionally they were also called “Marathonians,” after Marathonius of Nicomedia, another supporter of this teaching.