However, as the third season of excavations on the site drew to a close last month, archaeologists say it has yet to give up all its secrets.
One of the most significant discoveries of this year’s dig is conclusive evidence that the earliest viking houses, thought to date from around AD900, were preceded by a Pictish settlement.
This year, a team of nine archaeologists led by Dr James Barrett, of Cambridge University, revisited the trench they excavated in 2009, with the intention of digging further down to find the earliest evidence of human habitation.
It was discovered that the oldest of the viking dwellings had been built on the hard boulder clay of the Brough. However, between the houses, under smaller outbuildings that were not as deeply entrenched in the landscape, there is evidence, beyond doubt, of a Pictish settlement.
The archaeologists have taken samples from the midden of a Pictish house, and by looking at the animal bones and botanical remains they expect to ascertain a great deal about the culture of its inhabitants.
Dr Barrett said: “This year, we decided to stick with the trench we had opened previously and get to the bottom of it. In doing that, we hope to understand more about three things.
“Firstly, when was the viking settlement established and how long was it there. Secondly, is there any evidence for the interrelationship between the vikings and the population that was there before them; and the third thing is what can we discover about the Pictish settlement.”
The archaeologists excavated through four floors of the viking house, which is a classic dwelling in terms of its structure and layout, and were able to take samples from the first hearth there.
By archaeomagnetic dating the samples, in conjunction with radiocarbon dating discarded bones, and analysis of the artefacts found, they hope to confirm when the village was established.
One question that has yet to be answered though, is what happened in the transition between the Pict and the viking villages, and, as yet, no evidence has been found of an integration between the two.
“In terms of the contact between the vikings and the Picts, we’ve got this massive Viking Age settlement dug into a Pictish site, without there being evidence of a horizon of the mixing of the two cultures,” said Dr Barrett.
He continued: “We’ve seen that the viking settlement replaced what was there before.
“Having said that, there are a few caveats, and the first is we’ve found Pictish-style pottery in the Viking remains.
“We also don’t know whether the viking settlement immediately followed the Pictish settlement, or whether the Pictish settlement had been abandoned for some time before the vikings came.”
For example, if the first viking settlement was founded in AD1000, Dr Barrett said that there would probably have been a hiatus between the two villages, whereas if it dates to around AD800, then it is feasible that it immediately succeeded the Pictish village.
He hoped this would become clear once work to date the earliest viking remains and the latest Pictish remains was complete.
What is clear, however, is that the foundations of the 30 viking structures, still visible through the grass, were contemporaneous and were well entrenched in the Brough, which points to an enormous investment of labour.
Since the excavations began in 2008, archaeologists were quick to discount the theory that the Brough was a Viking Age ecclesiastical settlement.
All evidence so far, and the Brough’s location, indicate it was a high-status stronghold and a symbol of power and prestige.
“There has to be a reason for it to be there, and the reasons are finite,” said Dr Barrett.
“It has very good views of the sea and it is very visible from the sea, so a combination of these factors, along with the difficulty of access, must have something to do with it.
“When you stand on the Brough and look back to the land, all you see is grazing land, not farm land, so the site wasn’t about controlling farm land.
“On the other hand, if you turn around, you can look out over 270 degrees and what you see is the eastern approaches to Orkney, including Copinsay and the Horse of Copinsay, which were pilotage landmarks, first recorded in the 1700s, and the passage through which one must pass if one’s going into the heart of the islands.
“A settlement on the Brough would allow you to control this, both seeing and being seen, so you could go out to intercept shipping if you had some unwelcome guests.
“But the Brough could have also been the place where you stopped and got your ‘passport stamped’, or stopped to pay some sort of tax or make yourself known to the powers that be.”
Indeed, the Orkneyinga Saga recounts several instances where merchants were hailed and required to show their goods to the Earl, giving him “first pick”.
Dr Barret added that while the noust near the Brough made an excellent natural harbour, the water round the headland could be treacherous.
He said: “I think that might be part of the point. It’s a good harbour if you know it, and not necessarily a good harbour if you don’t — which is absolutely in keeping with the other characteristics of the site.”
There were several significant finds throughout the duration of the six-week excavation and these paint a picture of a Christian community of around 150 people living “everyday lives” on the Brough, as well as its military importance.
Dr Barrett said that some of the most inconspicuous items had been remarkably informative.
Among them were a small piece of stone schist – possibly part of a quernstone imported from Norway or Shetland – and several pieces of soapstone pot, again not native to Orkney, and an arrowhead.
A discarded half of a glass linen smoother, often associated with Viking graves, was also particularly informative as it provides further evidence of family life, as well as a link to pagan burial rituals.
Perhaps the most “fun” though, was the discovery of a viking gaming board, which subsequently went on display at the Deerness in 100 Objects exhibition.
“Some of the things from the site are objects that have to do with its existence as a chiefly settlement and there are others which are just about the people who lived there and the lives they led, and one of these is a viking gaming board,” said Dr Barrett.
“It’s actually a Hnefatafl board, a viking game which is a cross between draughts and chess.
“It’s got a centre king piece and pawns round it and we’ve also found a number of disc-shaped gaming pieces carved from stone or antler.
“One of them is quite fun because it’s carved in the shape of a sword pommel.”
Dr Barrett continued: “Whoever made it didn’t take a lot of care over it as the lines are all wobbly.
“It’s just something that someone’s made some dark night, maybe after they’ve had two or three drinks.”
He added that, following conservation work, his team had now also been able to identify several artefacts found in 2009.
For example, a copper alloy strip has turned out to be a pendant with indecipherable runic writing, and what Dr Barrett described as “nothing to look at, at first sight” is part of a viking brooch, which has been filled with lead to be used as a silver weight.
He said: “In Norway, at the same time, the way they made their bullion weights was by taking stuff they had stolen from Britain and Ireland — often ecclesiastical objects — chopping them up and filling them with lead.
“Here, a Norwegian object has been treated in exactly the same way. It’s probably unique.”
With the conclusion of this year’s excavation, Dr Barrett and his team feel the site certainly merits further investigation, although this will depend on future permission and funding.
The recent trenches were dug to look at viking settlements, but now the site of the Pictish remains has been found, an excavation focusing on them is one possibility.
Looking at the site in a wider context – perhaps its relation to the viking cemetery at the Bay of Newark, just along the coast, and other broughs in Orkney – is another.
In the meantime, Dr Barrett and his team will be analysing, conserving and recording the finds from this year’s dig, with the hope of returning, possibly in two years’ time, to continue their work.