Readers of history have for centuries been fascinated with the Fall of the Roman Empire, however inapt that designation may be. In a passage from his book The Origins of France, Edward James offers two reasons for the transition. The Romans settled the Visigoths in Aquitania as foederati, i.e. as a governing body acting on their behalf. The local aristocrats cooperated as a means of increasing their own authority in the changing regime, and in general the local inhabitants were tired of Roman tax burdens.
In his letters Sidonius paints a lurid picture of the ruin into which the Catholic Church in south-west Gaul was falling under Euric’s rule. Even as a bishop he preserved a considerable pride in his membership of the Roman Senate, and his letters tell us a good deal about its reactions to the Germanic invasions. Some senators continued, or feigned to continue, the traditional life-style, living in luxurious villas on their country estates, reading, writing, playing backgammon or a somewhat elementary ball-game… But others seem to have made a determined effort to exploit the new conditions, like Syagrius, who very sensibly (but to Sidonius’ open amusement and incomprehension) acquired a fluent grasp of Burgundian. Some aristocrats obviously welcomed the extension of Germanic power in Gaul. They preserved their estates (or the most profitable parts of them), and their social status, and in all probability they increased their political influence. Under Euric, Romans acted as advisers and ministers; one of Sidonius’ friends commanded Euric’s navy. For how many senators was Arvandus, the praetorian prefect of Gaul, speaking when he wrote to Euric suggesting that he make war on the ‘Greek’ Emperor (Anthemius, appointed in Constantinople), and divide Gaul up between the Visigoths and the Burgundians, ‘according to the law of nations’? Other sections of the populace may have viewd the disappearance of Roman rule with still less regret. The strange Christian moralist Salvian of Marseilles, one of the founders of the long-lived historical myth of the clash between late Roman decadence and Germanic virtue, pointed out around 440 how heavy the burden of Roman taxation was (a fact confirmed by modern research) and concluded that ‘it is the unanimous prayer of the Roman people in that district that they may be permitted to continue to lead their present life among the barbarians’.
Considering the numerical inferiority of the various Germanic groups that caused trouble inside the boundaries of the late Roman Empire—I recall an estimate that the Visigoths in Spain were only 1-2% of the population—in tandem with the many troubles at the boundaries, the system of using the Germanic groups as foederati makes good sense. The acceptance and persistence of this Germanic authority would still have to be explained, but this passage illuminates two very good reasons.