and Guy Halsall have argued instead that the barbarian groups crossed the Rhine not (so much) because they were fleeing away from the Huns, but seized the opportunity to plunder and settle in Gaul when the Roman garrisons on the Rhine frontier were weakened or withdrawn in order to protect Italy. Peter Heather (2009), on the other hand, argued that this hypothesis does not explain all the evidence, such as the fact that 'the vast majority of the invaders who emerged from the middle Danubian region between 405 and 408 had not been living there in the fourth century', and that the evidence for any Roman military withdrawal from the northwest at this time is weak; escaping 'the Hun-generated chaos and predation' was still a better explanation. Vandal–Frankish war According to the Frigeridus fragment, there was a war between the Franks and the Vandals, in which the latter were losing. MacDowall (2016) suggested this war may have consisted of several battles, wherein the Franks were trying to defend their own territory and/or the Roman frontier as foederati, while Vandals were trying to either obtain a similar foederati status as the Franks, Alemanni and Burgunds on the east bank, or trying to cross the Rhine. Frigeridus states that the Vandals lost around 20,000 warriors, including their king Godigisel, in these military engagements. When the Vandals' war situation was becoming desperate, the Alans (who he mistakenly labels Alamanni) came to the rescue of the Vandals, and the joint forces seem to have defeated the Franks in a decisive battle. Frigeridus does not mention a date nor a precise location for this battle; he only indicated that the Alan army 'turned away from the Rhine' in order to intervene in the Vandal–Frankish war, so it must have taken place some distance away from the river. MacDowall estimated that this last battle 'probably took place some time in the summer or autumn of 406, and it allowed the Vandals and their allies to move into Frankish territory on the middle Rhine'. Despite this, and against contemporary military logic of staying in the winter quarters to await more favourable weather for their next campaign, Prosper claimed the Vandals and Alans crossed the Rhine in the middle of the winter, which MacDowall argues would only make sense if they were starving and desperate, and the lands they had just conquered from the Franks were insufficient to