Thomas Cadbury, Assistant Curator at the Royal Albert Memorial Museum in Exeter on the Seaton Down Hoard, a colossal collection of 22,888 Roman coins discovered in an East Devon field in November 2013

Why would anyone bury 22,888 coins and not come back for them? It’s trying to get to the mystery behind the Seaton Down Hoard that intrigues me as an archaeologist.

The hoard weighs an incredible 68 kilos, I can’t lift the whole thing up, so it isn’t something one person can shift around and bury easily. Whoever was doing it was probably part of a team and they likely needed something on which to move it.

We found tiny traces of a container, a great big leather bag, so we know the coins were buried together at one time. Other coins hoards seem to have been little offerings made frequently, but we know this wasn’t one of those.

We think it was buried around AD 350 because the last coins are dated AD348, which would allow for them to circulate and get to East Devon. None of the coins were made locally – they come from as far away as Syria and Egypt and others were made in Turkey, but the vast majority were made in what was then Gaul (modern France and Germany).

There are so many of them it gives a really good snapshot of the kinds of Roman coins that were circulating in Britain at the edge of the Roman world at that point.

They are tiny nummi – Roman bronze coins with a small amount of silver in them. As the Roman Empire expanded they couldn’t afford to carry on making high quality silver coins so they replaced them with these bronze coins. The next era of coinage was even smaller and had even less silver in it, so one explanation as to why the coins might have been buried was that people were being faced with the new coinage and they were suspicious of it.

A few fields away from the find there was a large Roman site, which we think had probably been a big farm at one point or even a government waystation for officials going between Exeter and the continent, London or further East.

In the fourth century, when these coins were buried, it had probably reverted to a farming estate so I’m fairly convinced the coins relate to that site in some shape or form – possibly there is some connection to a cashiers office because they are the sort of every day coin used to pay agricultural labourers.

“The lowest paid agricultural labourer was only paid one nummus a day”

In size and weight they are similar to a modern penny but in terms of their spending power they are nearly equivalent to the modern pound. We have a few indications of Roman prices – two nummi would buy you a flagon of the poorest quality Roman wine. Better quality wine might cost you eight nummi. Sadly human labour was cheap, so the lowest paid agricultural labourer was probably only paid about one nummus a day.

But there’s a much larger geo-political story encapsulated in them. Most of them relate to the Emperor Constantine I who is known for the acceptance of Christianity and for establishing the new capital of the Roman World, Constantinople. The foundation of that brand new city is really marked in the coins.

They may have been made all over the Roman world but that message comes through loud and clear – ‘we have a new capital city!’ But in parallel, the old capital city of Rome is still to be venerated and that also comes through in the coins.

The acceptance of Christianity is much less explicit but we believe the depiction of a bridge on some of the coins refers to the Battle of the Milvian Bridge (AD 312), which brought Constantine to power. The story goes that the night before the battle Constantine had a dream in which he was told to display the Christian Chi Rho symbol on his army’s shields to secure victory. He did so and he won.

“There are many depictions of Helena (Constantine’s mother) and Theodora (Constantine’s step-mother); both formidable women and powerful political operators.”

The Chi Rho symbol was then adopted by Constantine and it also features on the coins, but then there are quite a few depictions of the sun god Sol, which is part of the ancient Roman pantheon. If you are trying to move people towards monotheism you do that by emphasising a single god in the pantheon.

As well as Emperor Constantine I and many other male emperors and sub-emperors there are also many depictions of Helena (Constantine’s mother) and Theodora (Constantine’s step-mother); both formidable women and powerful political operators who outlived Constantine.

There are also lots of coins that effectively depict the Roman military as a force for good, protection and security. There were however lots of civil wars and rebellions at this time, so the army being on your doorstep is probably a really bad sign that you’re close to trouble. The coins therefore become an important part of the propaganda message that the army is there to protect you.

The nearest town to the find location of Seaton Down was a Roman harbour and the end of part of the Roman road system. Various Roman finds have been uncovered in the area, was also know from reliable antiquarian references going back to the 1840s that there was a Roman Watchtower on a nearby hill, so it fits into that Roman landscape – with Exeter being the central point of that landscape. It’s the regional capital now and it was certainly the regional capital then.

There is a long standing myth that Exeter was a boundary of Roman Britain but more and more finds in West Devon and Cornwall suggest the Romans had been all over the south west peninsula from the start.

Probably even before the Roman invasion there had been long-standing trade links between pre Roman people and the Roman world on the continent. It’s almost as though people in the South West were so used to the Romans that they weren’t so opposed to the invasion. There is no evidence that the Roman military had to fight their way into the South West, whereas they had plenty of battles in Wiltshire and Dorset and Southern England.

In a way the hoard is perfect because one of the highlights of the collection at RAMM is our Roman archaeology – Exeter being an important Roman city with military origins right at the start of the Roman period in England. We have lots of finds from the Roman bath house, which is underneath the present Cathedral in Exeter and is the oldest known stone building in Britain.

Three hundred years later you have this coin hoard which almost marks the end of the Roman influence in the area, so it bookends our collection quite nicely.

The great things about the find is that it’s an amateur find by metal detectorist, Laurence Egerton, who had been going over the land for pretty much two decades finding some bits here and there. But he did everything right. As soon as he realised what he had found, he stopped digging and contacted the county archaeologist for Devon, who arranged for the coins to be professionally excavated.

We didn’t know much about the later Roman period in Devon, but now thanks to the coins, we do.

Thomas Cadbury was speaking to Richard Moss. The Seaton Down Hoard was declared treasure and processed through the Portable Antiquities Scheme see finds.org.uk for more and read the report.

The Seaton Down Hoard goes on display at the Royal Albert Memorial Museum in Exeter on July 1 2017. See rammuseum.org.uk/seaton-down-hoard/ for more.