Dr. David Gwynn

Sort out this revolt of Crausius and Electus, he's going to do that.

Galerius and Diocletian, interestingly, don't follow such a clear-cut geographic pattern.

Diocletian's chief residence is Nicomedia in modern Turkey.

Galerius has indeed left us the very few remains of a great arch in Thessalonica in Greece.

But it's also Galerius who gets the job of fighting the Persians.

So Galerius and Diocletian, it's much more a who's looking after what sphere rather than who's going to be in which region.

Diocletian is going to focus on the government, the economy, getting the internal structures working.

Galerius gets the job of facing the Sasanian Persians.

No, he's clearly a highly capable soldier or he'd never have risen through the ranks in the first place.

But like so many actually very good soldiers, his great strengths lie in logistics, in organization.

He's clearly a perfectly competent military commander, but the only struggles we see him directly involved in tend to be subduing revolts like in Egypt.

It's not in trying to win major battles.

The same is true of Maximian, whose most famous major campaign was the attempt to win in Britain that fails.

It does look like that one of Diocletian's criteria for the Caesars was these were going to be the men who were going to be active on the battlefield.

So Constantius is clearly very effective and very efficient in suppressing the British revolt.

It's Galerius who's going to achieve the greatest single military success of the Tetrarchy because the Sasanian Persians, who emerged in the 220s, have been fighting the Romans basically ever since.

And the Romans have never won a major conflict until in 298.

That's exactly what Galerius does.

And after all, what's going to be almost everyone's assumption when you have a tetrarchy?

There's a civil war coming.