Peter Heather

So if you think about that, it's a pretty hefty competitor.

Third Centurion's Crisis takes the form of various emperors being defeated by the Persians, and then various provincial subgroups breaking away from the center,

in response to the fracturing of imperial authority.

So the Persians challenge imperial authority on the battlefield, and then these provincial communities start setting up their own branches of the Roman Empire.

So we get a Gallic Empire that lasts for two generations in the second and third quarter of the third century.

Why this is important is the way that the empire actually overcomes the crisis then shapes the nature of where we are in the fourth century.

And in particular, I suppose two things stand out.

One is we refashion the military.

So gone are the legions.

Early Roman Empire, you have legions, big units.

There are 5,000 men.

There are a small expeditionary army in themselves, each one dotted around the edges of the empire.

It's a usurpation in waiting, basically.

In response to the breakaway units of the 3rd century, we create a hierarchy.

So there are still units on the frontier, but they're small.

They're not very well equipped.

There are some regional armies, intermediate forces,

But the real striking power of the imperial army is concentrated in elite formations around the empire.

Absolutely.

No political dissidence after the year 300 takes the form of a frontier or a regional commander challenging central imperial authority.