Choricius of Gaza describes Aratius as originating from a good family and having distinguished brothers.
The battle is briefly described by Procopius: "And the Romans, under the leadership of Sittas and Belisarius, made an inroad into Persarmenia, a territory subject to the Persians, where they plundered a large tract of country and then withdrew with a great multitude of Armenian captives.
These two men were both youths and wearing their first beards, body-guards of the general Justinian, who later shared the empire with his uncle Justin I.
But when a second inroad had been made by the Romans into Armenia, Narses and Aratius unexpectedly confronted them and engaged them in battle.
Procopius narrates: "Narses and Aratius who at the beginning of this war, as I have stated above, had an encounter with Sittas and Belisarius in the land of the Persarmenians, came together with their mother as deserters to the Romans; and the emperor's steward, Narses, received them (for he too happened to be a Persarmenian by birth), and he presented them with a large sum of money.
When this came to the knowledge of Isaac, their youngest brother, he secretly opened negotiations with the Romans, and delivered over to them the fortress of Bolum, which lies very near the limits of Theodosiopolis.
For he directed that soldiers should be concealed somewhere in the vicinity, and he received them into the fort by night, opening stealthily one small gate for them.
He is then credited as the strategos (general) responsible for capturing an enemy fortress, which was considered impregnable.
He is thirdly mentioned leading a force of about 20 men in opening a pass which was held closed by Arab attacks.
He is next mentioning restoring Byzantine control over Iotabe (Tiran Island), previously occupied by neighbouring tribesmen.
[1] Choricius' flattering description features Aratius as an able man, merciful in administering justice and honest in financial matters.
In 540, Aratius, his brother Narses, Bessas, and John fell out of favour with Belisarius and sent away from Ravenna.
Aratius presumably continued fighting the Gothic War, but his activities over the following decade are mostly unrecorded.
Aratius, Bouzes, Constantianus and John were tasked with leading a force of 10,000 cavalryman on a mission.
This campaign was short-lived as the two opponents concluded a peace treaty, making the presence of Byzantine forces unnecessary.
[1] In early 551, Aratius was one of the military commanders sent to face the South Slavs who were plundering the Balkans.