Professor Rob Collins

And so if we think about, because we don't have the historical text that gives us that really easy answer, what we do have is excellent archaeological evidence.

So we need to think about how we use that evidence to understand those relationships and is this frontier system still in operation?

There absolutely is some sort of cutoff point, but we can't define it precisely.

And this is the challenge.

But what is great is that even really in the past 10 years, some of the scientific techniques that have emerged, actually I think we can start applying to really try and solve this problem.

And so one of the things, a key form of evidence really, partly is it always is in archeology, but it's pottery.

Pottery is robust.

It survives very well.

And what we have very clearly demonstrated throughout the entirety of the fourth century, and so this is something we can be confident of, will continue into the fifth century, as long as we have a Dux Britanniarum to direct the resource.

are what we call the Yorkshire ceramics.

So things like Cranbeck ware for the fine wares, the nice plates, the things you eat and drink out of, and the Huntcliffe type wares for course wares, cooking pots and things like that.

Those are made in North Yorkshire, not too far north of York, in fact.

And we can look at a national distribution of that pottery.

They start to emerge in the third century, but in the fourth century,

they jump up and they become the most predominant sources of ceramics all along Hadrian's Wall.

And there's, I don't know, 85 to 90% of all the ceramics we find in those late Roman wall forts.

So it's a regional ceramic industry.

And it's really serving the Roman army because actually outside of the, if we say the greater Yorkshire region, those ceramics are only really getting to the towns and to the forts.

They're not widely distributed into the countryside.

We're not seeing all the rural farmers using them.