By Nick Gaukroger
army list covers Roman armies from the time of Septimus Severus to that
of Constantine—and we have used the date of Constantines undisputed rule
over the whole Empire. Septimus Severus recruited new legions and
reorganised others, dismissing the Old Praetorian Guard and refounding
it using loyal troops from the legions—so it is a good point in terms of
characterising developments in the Roman military.