During its heyday the Roman Empire sprawled across the better part of three continents, making it one of the greatest political bodies of its day. To maintain such an empire required an enormous military budget and huge numbers of men at arms (an approach to militarism we can, alas, observe to this day). One of the chief duties of this sprawling military was to hold the edges of this empire from incursion from without.
Osprey Publishing and author Raffaele D-Amato have put together a surprisingly exhausting study of the military units comprising Rome’s Western borders – more specifically, what would someday become England, Germany and France.