A.D. 381 heretics, pagans, and the dawn of the monotheistic state ( PDFDrive )

Valentinian’s own commanders were determined to maintain their status against
this inexperienced newcomer, so they declared Valentinian’s youngest son, also
Valentinian, as his fellow emperor, Valentinian II. Even though he was only four,
they gave him nominal responsibility for the provinces of Italy, Africa and
Illyricum, which they could then rule on his behalf. Ostensibly, it was a direct
affront to the dignity of Gratian, but the atmosphere of crisis was such that
Gratian had to condone the move. He did his best to reassert control by moving
Valentinian into his court at Trier.
So Valens, in the east, suddenly found himself the senior of the three
emperors, but he was now without the support of his formidable brother and with
only two young nephews as his fellow rulers. It was unlucky that there were
signs that the northern borders of his part of the empire were also troubled. At
first it was not clear what was happening, but there were dispatches telling of
masses of Goths migrating southwards towards the Danube. Shadowy reports
suggested that beyond them a new people, the Huns, had been sweeping across
the steppes from the east. ‘This wild race, moving without encumbrances and
consumed by a savage passion to pillage the property of others’ was how
Ammianus Marcellinus described them. 5 The Goths were refugees from the
onslaught of the newcomers, and before long they were crowding along the
banks of the Danube. The first that Valens may have heard of the crisis was in
the autumn of 376, when envoys from the Goths arrived in Antioch, five
hundred kilometres away from the border, pleading to be allowed into the
empire.
Valens’ response was probably dictated by his desperate need for manpower.
He knew that here would be several thousand young men who would be glad of
a place in the Roman armies, while other migrants could be settled as peasant
farmers and then made subject to Roman taxation. This had happened before - it
was one of the many strategies the Romans, who were always pragmatic in such
things, had adopted in order to keep peace on the borders. It was essential, of
course, that the migration should be orderly so that the newcomers could come
under direct Roman influence and be found land where there was room.
Accounts of earlier migrations - there was one of another tribe, the Sarmatians,
in 359 - show that a contingent of Roman troops would supervise the movements
of the incomers.
Valens learned that there were two tribal groups of Goths assembling on the
banks of the Danube: the Tervingi, under their leader Fritigern; and the
Greuthingi. In order to keep control of events, he ordered that the Tervingi