Late Roman Unit Sizes

[ValentinianVictrix]

Michael, my research indicates that both Palatine Legions and Auxiliary units could, and often were, brigaded together. And it was not always the same two units either, although in most most cases it was the same two. The Lanciarii and Mattiarii appear to be brigaded together during Julian's Sassanid campaign, as were the Herculanii and the Iovanii Legions. The Lanciarii and Mattiarii were brigaded together at Adrianople.

Indeed, but in those instances do they preserve their separate identities? If Malalas is suggesting that this was a vexillation made up of elements from the two units (and, of course, I take Macedon's reservations into account), it would make sense, as they were used to working together. Incidentally, Ammianus 14.1.2 confirms the number of 1500. Rolfe's translation calls them 'mounted scouts' but Ammianus says nothing about their being mounted. The word he uses is excursatores which my dictionary calls 'skirmishers' but I suppose that, in this context, 'scouts' would do just as well. This said, the doubts about Malalas mean that it would be unsafe to rely upon him.

You raise an interesting point here Michael. When Ammianus describes troops that have been detached for special duties as 'expediti', and this was applied to both infantry and cavalry. Yet in this instance he uses the term 'excuratores', and I'm struggling to recall if he used that term again in his history to describe detachments. I'm not sure if the description of 1500 men means 750 are detached from the two legiones or 1500 were detached from from them. Either way I would suggest that even if it was the lower figure then the legiones must have been larger than 1500 men strong because I cannot see anyone sending half of each unit on an operation.

I think we can all agree that it was the two Legiones rather than Evans suggested units.