The Roman army and military defence in Northern Gaul and the Germanic provinces during the Late Empire

Late Antiquity was a time of permanent mutation, with substantial changes affecting the army, which was regularly subjected to reforms. The successive stages of evolution are incompletely documented. ¹ These changes had strategic consequences. ² Military systems were adapted to the geopolitical situation of each region and benefited from new construction or restoration initiatives decreed by the central authorities. ³ Some have argued for the appearance of a new overall military strategy during the Late Empire, but this hypothesis is not justified by the evidence. ⁴ In fact we should consider a number of factors that were in play: the decisions of individual emperors and the actions of senior commanders who often adopted similar measures, ranging from restoring a situation that had been destabilised by crisis – provoked by either internal strife or external invasion – to modernising the military toolkit. We also have to take into account a decline in military manpower over time, ⁵ the dispersal of soldiers into smaller units, and the increasingly multicultural recruitment of military forces, a trend that would pose problems of its own. ⁶