The Dynasty of the Roman Empire

The Romans have a very well-practiced and choreographed routine for trying to deal with attacks on the frontier. And it's all about divide and rule. It's about finding someone who's willing to work with them and using that partner to help to control the situation north of Danube. The Goths are given special trading relationships, which is why all the stuff then flows across the Danube. Rome looks on occasion to borrow military or actually hire military support from Goths for campaigns against the Persians.