Saint Artemius or Nicetas, he could not be identified with certainty.

From the Wikipedia: “Artemius (d. in Antioch, 362), known as Challita in the Maronite tradition, was a general of the Roman Empire, dux Aegypti (imperial prefect of Roman Egypt). He is considered a saint by the Orthodox Church, with the name of Artemius of Antioch. Artemius was an Egyptian by birth and a chief commander under Emperor Constantine the Great. Constantius II ordered Artemius to go in the lands beyond the Danube and to bring back to Constantinople the relics of Andrew the Apostle, Luke the Evangelist and Saint Timothy. Artemius accomplished his task and was rewarded with the appointment to the rank of dux Aegypti (360). One year later Constantius was succeeded by his cousin Julian, who was a Pagan. The people of Alexandria accused Artemius of having demolished their temples, and broken down their idols, and Julian condemned him to death. Artemius was beheaded in 362 in the city of Antioch, where he had been recalled by Emperor Julian the Apostate for maladministration of his province. The charges stemmed from his persecution of pagans in Alexandria, and his use of troops in the seizure and despoliation of the Temple of Serapis (Serapeum of Alexandria) instigated by George of Cappadocia. According to Ammianus Marcellinus, his death encouraged the people of Alexandria to kill George, but this information is probably false, because George was already dead before his trial.” I suggest to leave out the “probably” in the last sentence.
Nicetas (Russ. Никита Nikita, Ukrain. Микита, from Greek Νικήτας Niketas) is a Christian martyr of the 4th century, venerated particularly in the Russian Orthodox Church. His feastday is 15 September. Nicetas, a Gothic soldier, lived in the Danube region at the margins of the Eastern Roman Empire. Presumably, he received his Greek name on the occasion of his baptism by the Gothic bishop Theophilus, a participant in the First Ecumenical Council. Pagan Goths began to oppose the spread of Christianity, which resulted in internecine strife. Nicetas fought in the Gothic civil war between the pagan Athanaric and the Christian Fritigern. After the defeat of Athanaric, Nicetas worked with Ulfilas in converting the Goths. He was condemned to the stake in 372. According to his Passio, the devil, shaped as an angel, induced Nicetas to sacrifice to the pagan gods for saving his life; Nicetas, however, put him to flight by means of prayer and assisted by archangel Michael. His body was buried it in Cilicia, and later transferred to Constantinople. In Russia, Ukraine and Serbia, there are several churches and monasteries named after St Nicetas. See Church of Saint Nicetas. St Nicetas is prayed to for the preservation of children from birth defects."