The Brough of Deerness from the landward side of the original land bridge.

Jutting out into the North Sea, on the north-eastern coast of the Orkney Mainland, is a large grassy rock known as the Brough of Deerness.

Measuring 80 metres wide, and surrounded by 30 metres sheer cliff faces, on top of the Brough are faint traces of a settlement, surrounding the visible remains of a 10th century chapel.

The site was once connected to the Orkney Mainland by a land bridge, but a geologist's examination in 2008, confirmed this had crumbled away a long time before it was occupied.

Now the site is not one of the easiest to reach - the visitor must first negotiate a slippery and muddy descent to the bottom of Little Burrageo, before a steep, narrow ascent along the south face of the Brough to reach the summit.

Once on the Brough, the visitor will immediately spot the remains of the chapel, which stand four of five feet high. Dating from the late Norse period, this chapel is the focus of a complex archaeological mosaic, consisting of a bank and wall and a tight cluster of an estimated 30 structures.

The Brough of Deerness, as seen from Little Burrageo. The path leading to the summit of the Brough is on the facing rock face.

Because of the account of the Brough by Jo Ben, allegedly dating from 1529, it had been known for some time that the land bridge must have collapsed before the 16th century.

Jo Ben wrote:

"In the north part of the parish there is, in the sea, a natural rock where the people on hands and knees ascend to the top with great difficulty."

In addition, the site is referred to as the "Borch of Dernes" in a 14th century list of islands in Orkney, compiled by John de Fordun.

However, during long-awaited excavation of the site in 2008, an examination of the area highlighted a geological fault - a fault, which saw the land bridge collapse a long time before the Brough settlement.

The project’s geologist, Professor Donna Surge, was clear: “There could not have been a land bridge there 1,000 years ago.”

Brough of Deerness resistance data, clearly showing the outline of a number of buildings. (courtesy of ORCA)

Instead, she suggested a bridge had been constructed to provide access. And that at the Brough-side of this bridge, which would have been no mean feat of engineering, was a defensive rampart.

This defensive structure, with masonry showing on the landward face, is still clearly visible  and has led to much speculation over the years.

Some suggested it represented Iron Age earthworks while others declared them to be a “Vallum Monasterii” — a symbolic barrier for the theoretical monastery.

However, the 2008 excavation director, Dr James Barrett, from the University of Cambridge, felt that, based on the current evidence, the bank and wall was a Norse construction, although possibly reusing an existing feature, was defensive and controlled access to the site — another outwardly visible show of power, prestige and wealth.

Despite excavations on the Brough in the 1970s, until 2008, nothing was known about the site to allow it to be dated exactly, or even show what it was used for. But a five-week excavation, by the University of Cambridge, remedied this.

From the late 19th century, the idea that the Brough was an early, pre-Norse, “ecclesiastic settlement” became common. This theory was first aired in 1879, and subsequently gained antiquarian popularity. More recently, however, scholars firmly placed the rectangular buildings in the Viking era, dating from the 11th and 12th centuries.

Working down through the floor levels of one of the suspected 11th century Norse houses.

A paved area outside the house's entrance.

From work so far, Dr Barrett feels the Brough was the site of a Viking chieftain’s settlement — a fortified stronghold that was also a visible show of power and prestige.

“In the past it’s sometimes been a matter of academic fashion as to whether it was declared monastic or a defended site. At the moment I’m leaning toward this site as being a chiefly settlement, rather than a monastic enclosure,” he said.

“Chris Morris, who excavated the chapel in the 1970s, first raised the idea that the Brough was a chieftain’s stronghold, and the new evidence is pointing in that direction. If, for the sake of argument, we say it was a chiefly site, then why here? It’s very strange. At the end of the day, I think it comes down to somebody making a point.”

The 2008 excavations uncovered the remains of two Norse houses. Although full examination of the artefacts found inside will be required to provide a precise date, Dr Barrett suspects the structures date from the 11th century and are, therefore, contemporary with the last phase of the nearby chapel.

“Although we’ll never be able to directly link the settlement, stratigraphically, to the chapel, there were a number of burials found during the excavation of the chapel in the 1970s. One of these was buried against the chapel wall, and was radio-carbon dated to the 11th/12th century. From this, we can see that the chapel is contemporary with the later settlement structures.”

The architecture of these Norse houses is particularly intriguing. They follow a plan commonly found in Viking-Age Dublin — making the cluster of houses reminiscent of an urban housing site in a rural location.

Although the buildings were built into earlier structures, it’s not yet clear what these are — whether Norse or earlier.

That the excavated later structures were domestic is without question — finds included loom weights, soapstone pot, pottery and a spindle-whorl — but there also appeared to have been metalworking carried out on site. Used mould sections were found, but these were too fragmented to allow the archaeologists to ascertain what they were used for.