What happened next? As Roman exhibition comes to an end we look at Norfolk’s role in the fall of the Empire

Roman walls at Venta Icenorum at Caistor St Edmund near Norwich.; Photo: Bill Smith edp 8/5/02 (Image: Archant)

We all know the tale from our schooldays, one of the most poignant stories in history.

Part of the hoard of rare Roman glass found at Hockwold-cum-Wilton (Image: Archant)

Sometime around the turn of the 400s, the Roman emperor orders the legions to leave Britannia, leaving the Britons to wave a sad goodbye - and quiver defenceless in our towns and villages as we eye the uncouth Saxons gathering on the horizon, sharpening their axes...

Part of the hoard of rare Roman glass found at Hockwold-cum-Wilton (Image: Archant)

Roman expert Dr Adrian Marsden laughs. 'It's absurd! This picture of these guys in plumed helmets arriving in AD43 and then packing their bags and sailing away...'

This old Victorian idea is still a powerful one, but Dr Marsden believes the true story is much more complicated and fascinating that that, and may have some powerful insights into our sense of our own Norfolk identity today.

For a start, there is growing evidence that the Saxons didn't 'invade' at all: they were already here, employed to defend the very empire history says they were gathering to overthrow.

The story of what may have happened begins with the famous Saxon Shore forts such as Brancaster and Burgh Castle. The key issue is what 'Saxon Shore' meant. 'There are three theories,' Dr Marsden explained. 'That it comes from the coast the Saxons attacked, or that they garrisoned the forts, or from the 'Saxon Sea'.

'I suspect the garrison theory is most likely, especially given the fact that Norfolk links with the mouth of the Rhine go back a long way.'

A 'long way' is actually hundreds of years. 'There is a strong possibility that the legends on Iron Age coinage [coins from before the Romans invaded] are actually in a Germanic language and not a Celtic one. Which means that the Iceni - or their ruling classes - came from Frisia or that area.'

So just think: Boudica - 'our' Boudica - might have actually been German.

'It would possibly account for people coming over later: they were linked by family connections that went back hundreds of years,' Dr Marsden continued.

You might look at the map and think of Norfolk as vulnerable - hence those forts. But Adrian is having none of it. 'Apart from the aftermath of Boudica's revolt, we just don't have a strong military presence in Norfolk until the third century. One argument - which I think is quite compelling - is that the Saxon Shore forts were there to protect the fleets which carried grain from Britain to the Rhine Valley.'

The grain was probably grown in the West country and around the fertile soils of the Fens. There was an Imperial estate based at Stonea, near March, which shows how important (and lucrative) the grain trade was.

'We know that grain was being shipped in the 350s and it may have been shipped for some time. This casts into quite stark light that it wasn't gold the raiders were after - it was food.'

With Gaul (Roman France) constantly ravaged by warbands, the tribes looked to fertile Britain as an easy source of supply. The Roman writer Vegetius tells of camouflaged ships moving in convoy, with 'wolf packs' of raiders trying to catch them. Sounds familiar? U-boat tactics 1,500 years ahead of their time...

Trying to stop these opportunistic raiders were the Roman troops, many of which were Saxon mercenaries, recruited into an army increasingly manned by foreign soldiers. 'The late Roman army was very heavily 'barbarianised'. The classic legion that we associate with the Romans had simply ceased to exist.'

It's very significant, Dr Marsden believes, that the metal finds we find on very early Anglo-Saxon sites have strong army influences. 'All early Saxon metalwork in Norfolk is clearly derived from military patterns. It all looks distinctively 'official'.'

And Dr Marsden, a coin expert with the Identification and Recording Service based at Norwich Castle Museum, thinks we should forget about Norfolk and the rest of Britannia as being weak and isolated.

The fact is, these islands were so fertile and such a good power base that they produce a string of would-be emperors over the centuries. 'There was still a large standing army [in Britannia]. Even though it was smaller than at the start of the province it was still something to be reckoned with.'

As the last decades of the fourth century wore on, the once-mighty empire began to buckle, then crack, under a whole series of factors - political, military, economic and many more.

With the Roman economy unravelling, first one industry then another faded away. Coins became valueless, trade routes faltered. 'Here in Norfolk we had the glass industry around Hockwold which imported glass 'ingots' from Egypt. When that route stopped, so did the industry. We see a similar thing with the Nene Valley and Brampton pottery industries.'

It's around this time that people started burying their wealth, trusting more to the 'Bank of Hiding' than risk having it grabbed by rapacious tax officials or unpaid troops on the look-out for easy cash. That has given us such amazing finds as the Mildenhall, Thetford and Hoxne Treasures.

With falling demand for luxury goods and trade routes collapsing, everything started to unravel. And with no markets, what use towns?

Which brings us to the question of what happen at our biggest Roman town - Venta Icenorum (Caistor St Edmund).

'We don't think Venta was ever abandoned. From the Dunston Field outside the walls we recovered more than 1,000 Roman coins, overwhelmingly fourth century.' There is strong evidence that this settlement continued - 'after a fashion' - for hundreds of years.

It seems the people simply moved outside the town and carried on living there, abandoning Roman-style buildings for simpler (and cheaper to build and maintain) wooden houses.

'Apart from one dodgy burial from the fourth century outside Venta - a body flung into a hole - there was no evidence that it was anything to do with the Saxons.

'There is no reason to presuppose that it was a violent transition. If you've got the Saxons acting as a late Roman army, then when the money ships stop coming in in 402 or 410 they didn't sail off to France. They just went native. They started taxing the inhabitants and became the new elite.

'There was a power vacuum and they were there to fill it.'

From this confused picture of local warlords taking power across the country comes the earliest stirrings of the legend of 'King Arthur'. Forget about the medieval idea of the 'knight in shining armour' and his chivalrous knights. This Arthur - if he existed, probably in northern Britain - was a very different person altogether. As the word 'Arthur' means 'bear', chances are he looked more like Hagrid than the brave knight of legend.

Norfolk must have had its similar strong-arm local leaders, ex-army commanders backed up by their warbands and imposing some sort of rough order in return for food and other booty.

There's another dimension to all this, and that is religion. 'There is a real absence of evidence for Christianity in Norfolk - we must have been die-hard pagan,' Adrian explained.

He has recently been doing research into such fascinating evidence as a raven cult which once existed in north-west Norfolk, and which must have gone back hundreds of years. 'Branodunum' - the Roman fort at Brancaster - literally means 'Raven Fort'.

The raven was a big figure in northern religions (well, have you ever seen a Hollywood Viking epic without one cawing in the background? Me neither). So was this another strong indicator that the Saxons were here all the time?

As the empire collapsed, it wasn't long before another great human trait kicked in: nostalgia.

The crude early Anglo-Saxon coins of the 650s, the 'sceatta', were copying the Romans, however badly.

They still looked to 'Romanitas' - 'the glory that was Rome' - for inspiration even after the Empire had tottered and fallen. It was the first expression of a theme that echoes throughout history right up to the present day.

'There is an argument that the Celts had a thin veneer of Roman paint. When the Romans cleared off there went back to being Celts again. That's not so - they looked on themselves as the heirs of Rome,' he added.

So will we ever get to the truth of what happened in these chaotic decades, more than 1,500 years ago, what historians used to call the start of the 'Dark Ages'?

Maybe. It all depends on our point of view. 'The evidence IS there - it's a question of interpreting it several ways.'

And Dr Marsden doesn't ever see this mysterious period ever losing its fascination for us. 'You've gone from a great empire a few years before which spread across the whole of the Western world. A generation later it's not there any more.'

You have just eight days left to visit the hugely popular exhibition Roman Empire: Power and People, running at Norwich Castle Museum to April 27. This British Museum touring presentation - for which the EDP is media partner - is the biggest archaeological exhibition at the castle since 2005, and features hundreds of exhibits.

There is a full programme of events running alongside the exhibition. They are: today and next Saturday - 1pm (rated U, for children and families) and 2.30pm (rated 12A, for older children and adults) Pompeii Live, film exploring the wonders of the 2013 British Museum exhibition, Castle Lecture Theatre, included in museum admission; Sunday April 27 - 1-4.30pm, Roman Finds Day, bring in artifacts for identification and enjoy presentations about recent discoveries, included in museum admission.

www.museums.norfolk.gov.uk