He engaged in efforts to evangelize Susa, traveled widely in the Eastern Roman Empire and led the opposition to Papa bar ʿAggai and the supremacy of the bishops of Seleucia-Ctesiphon in the Persian church.

[3] Sozomen in his Historia Ecclesistica, written in Constantinople in the first half of the 5th century,[3] briefly summarizes a Syriac account of the life of Miles.

[7]) In the Greek synaxaria it is found as Μίλλης (Millis, Milles),[4] Μίλης (Milis, Miles) or Μίλος (Milos).

Not long after, continues Sozomen, the city incurred the king's wrath and was destroyed by an army with three hundred war elephants.

[5] Miles was the main opponent of the claims to primacy within the Persian church of Papa bar ʿAggai, the bishop of Seleucia-Ctesiphon.

[12][5] The account in the Synodicon is contained in a purported letter read into the record of the synod of Patriarch Dadishoʿ (424) by Bishop Agapetus.

"[12] Before Papa was struck down (by a bolt of lightning in this account), Miles explained to the crowd that God would punish him for his pride.

[16] Jérôme Labourt suggested, on the basis of the inclusion of Miles' otherwise unknown companions at the end, that it may combine traditions associated with several different martyrs.

[20] The Menologion compiled for the Emperor Basil II around 1000 contains a depiction of the martyrdom of Miles, Aborsima (Eubores) and Sina (Sebon) for November 13.

[21] The iambic calendar of Christopher of Mytilene (early 11th century) contains the same three (Miles, Eubores and Senoi) plus Papas.

[22] There was a monastery dedicated to Miles at Lycaonia in Asia Minor in 596, when Pope Gregory the Great wrote a letter in Latin to its abbot, Athanasius, absolving him of heresy.