Threw this one out there in my Grab Bag post, but I've got a developed enough idea that I want to devote a full thread to it. Here's my chain of events, which should work out, but due to the ambiguity of the events and dates involved, who knows if it would?
- In AD 374, Emperor Valentinian receives an envoy from the Sarmatians and Quadi, who are currently raiding Pannonia in reprisal for the murder of one of their kings by a Roman official, Marcellianus, during a banquet, begging the Emperor to intervene in the situation. Valentinian, upon reviewing the circumstances, decides to find Marcellianus guilty and exile him, while coming to terms with the Quadi and Saramatians.
Historically, Valentinian sided with Marcellianus, waged war against the barbarians, and, upon finally accepting their surrender, got so ticked off by their attitude that he suffered a stroke and died. Due to his death, conspirators against Theodosius the Elder (father of the future Emperor) seem to have been successful in getting him executed, despite being a loyal and capable lieutenant, and sending his son into exile in his home in Hispania, from his post as Dux of Moesia. The Theodosians were too useful to be eliminated.
- In AD 376, a coalition of Goths under the pro-Roman Fritigern reach the Danube frontier, fleeing from the Huns. Appealing to Valentinian's brother Valens, Emperor of the East for asylum, a portion of the Goths are granted asylum, but all the Goths push over the frontier, rather than face the Huns, and are assembled into a de facto refugee camp near Marcianople, in Moesia.
As per history.
- The Dux of Moesia, Theodosius (the younger) arrives on the scene of the large group of disgruntled but not hostile and - most importantly - starving Goths. They were much larger force than the Romans had granted asylum and, even worse, they were still all armed, in direct violation of normal Roman procedure in settling barbarians within the Empire. Theodosius, however, handles the situation fairly well, essentially bartering grain to the Goths in exchange for their weapons, while buying time to accumulate a larger military force. Once the Goths are disarmed and the legions are on the scene, Theodosius negotiates with the Goths fairly, but absolutely according to standard Roman settlement practices: The Goths remain disarmed, and are broken up as a group, settled peacefully in various, disparate regions within the Empire, their tribal structures dissolved and the leadership of said tribes divested of their power. The crisis passes, and the Empire trundles on.
*Huge* difference. The Goths were so badly mistreated outside of Marcianople, being forced to sell their children into slavery for food, and, like the Quadi, their leadership was attacked during a banquet, that they revolted and defeated the Emperor Valens when he attacked. When Theodosius finally went to battle against them, he agreed to allow them to settle in one group, setting the precedent that went on to seriously undermine the Western Roman Empire.
- Post AD 376. Valentinian and Valens continue to rule, with Valentinian's sons, Gratian and Valentinian II being groomed. Theodosius the Younger marries into the dynasty. The Empire is a few ten thousand Gothic recruits stronger.