14 Jun 2020
The Brochs of Gurness and Midhowe on Orkney – Their Function in Iron Age Society
Brochs are quite frequent in northern Scotland; the remains of some 500 can be found on Orkney, Shetland, the western isles, and Caithness on the Scottish mainland down to the Great Glen. Further south, stone brochs are almost nonexistant. But few are as well preserved and impressive as the Broch of Gurness on the Orkney Mainland and Midhowe Broch on the island of Rousay.
Midhowe Broch with outer walls
The first essay about the brochs of Gurness and Midhowe will deal with the historical and socio-cultural context of the brochs, while further posts will have a closer look at the buildings themselves. Illustrations are from both brochs.
Broch of Gurness
The outer defense walls and dykes of Midhowe have partly collapsed or are bridged, but some local farmer found a new way to defend the building: The way leads some hundred metres across a meadow which had been freshly fertilised with slurry. I spent an hour cleaning my shoes in the evening. But it was worth some muck. Visiting its twin on the other side of the Eynhallow Sound, the Broch of Gurness, turned out to be less of an adventure.
Midhowe with the geo dyke in the foreground, seen from the south-east
Midhowe and Gurness are two of several brochs that once lined the shores of the Eynhallow Sound, but most of the others have been collapsed into heaps of stone, were slowly eroded by the sea, or are still buried under grass covered mounds.
Those brochs were built between 600 BC and 100 AD; the one of Midhowe dates to the later centuries BC, the Broch of Gurness to about 400 BC. They were in use at least until the first century AD, and may have been reused in the the 4th to 6th century AD.
Broch of Gurness, seen from the north-west
A broch is a circular drystone structure. The word derived from Old Norse borg which means 'fortification' (see also German Burg = castle). The same root can be found in the word ‘borough’.
The brochs developed out of the stone built roundhouses that were common in northern Scotland since the Bronze Age (in the south, roundhouses were mostly built of timber).
Midhowe, seen from the hill at the road
Those buildings were usually between five to ten metres high; sometimes even higher (the broch at Mousa on Shetland still rises to 13 metres). They usually have double walls with a staircase running inside the cleft to access the upper floors. The single entrance was a door on ground level, often with additional protections like double gates with a passage and guard chambers. Windows are seldom found, but the thatched roof had a louver.
Midhowe, the entrance
The interior of the ground floor level consisted of a central hearth (a feature already found in the Neolithic settlement at Skara Brae) and a series of chambers along the wall which were partitioned off by stone slabs. Since the interior floors were made of timber, nothing remains to tell us the exact layout of the upper floors, but it seems that they were usually not partitioned. A smoke hole in the centre – which was also used to smoke meat and fish – went through all storeys.
The exact structure of the upper floors is still discussed since no timber features remained. In some cases, they may have been galleries overlooking the central hearth rather than complete storeys.
Gurness, the central hearth with some partitions in the background
It took architectural skills and engineering knowledge to erect those double walled structures. The base is wider to carry the weight of the stones, and the double walls not only offer space for a staircase, but were additionally stabilised by insertion of horizontal stone lintel slabs connecting both walls at intervals. That way, a broch could be built higher. The builders needed knowledge about stress and pressure of higher walls to achieve a balance. The roofs were thatched, probably in a domed layout to allow the water to run off. Stone was not used for those domes (other than in the – much lower– cairns).
Gurness, the double walls with lintel connections
The brochs across northern Scotland and the islands are built to a similar design. This has led to the theory of traveling master craftsmen who took up commissions for building brochs by chieftains who wanted a fashionable abode. This theory has recently been confirmed by Dr. Dimitris Theodossopolous, Lecturer of Architectural Technology and Conservation at the University of Edinburgh, who specialises in broch architecture. Makes you wonder where they learned their craft and if there was some sort of centre, a school of broch building somewhere. As far as I could find out, there are no examples of less well built 'test' versions of brochs (like it is assumed for the Bent Pyramid).
Midhowe, additional buttresses along the collapsed wall
Sometimes broch walls did collapse, though. Midhowe is an example – it has been repaired by putting stone slabs against the wall as additional buttresses.
It had been assumed that there was an inherent weakness in the construction that led to damage during the use over time, but Dr. Theodossopolous thinks it more likely that the damage was caused by geological shifts. Coastal erosion can lead to a minimal sinking of the rocks some distance inland, and such a small shift would be enough to lead to cracks in the drystone walls which would then widen with the inflow of rainwater and frost. He demonstrated the stability of a broch in a model where the collapse of a part of the wall only happened when he destabilised the basis.
Midhowe, interior of the broch with hearth
Today, the landscape of Orkney consists mostly of meadows, heather and some bogs, with almost no trees. But once the islands were covered by dense forests of hazel, birch and willow on the lower levels; the hills were covered by open woodlands, meadows and heath. Human activities and climate changes led to a significant decline in forests in the late Neolithic / Chalcolithic (3,500 BC) – which is the reason stone was used as building material in increasing amounts.
Typical Orkney landscape today
During the Bronze Age, the temperature dropped, while at the same time the rainfalls increased, which led to a spread of peat bogs and heath at the cost of farmland. By the middle of the Bronze Age, the fertile soil concentrated in the low parts of the islands, and by 600 BC, Orkney looked pretty much like today (except for the modern buildings), with the same wet and windy weather.
Midhowe, view to broch with outer walls in the foreground
It is assumed that the climate change and decrease of farmland led to a change in society and perhaps to a time of unrest as well, since the patches of fertile land were contested. We don’t know much about the structure of society at the time, but it is likely that the people were organised in tribes or clans, led by a chieftain. Weaponry – together with other items – changed from bronze to iron, which may have had an effect on society.
Gurness, outer walls and dyke
The question whether the brochs were defensive structures or monuments of some sort is still discussed.
Brochs would have stood out in the landscape as monuments, but there are defensive structures like additional outer walls and dykes as well. And the broch walls itself would have been almost impossible to break with the technology of the time. Another argument if favour of defenses are the elaborate entrances laid out to control who entered the broch. Though no broch shows traces of armed conflict, like a burnt layer or delibarate destruction.
Gurness, double gate entrance
On the other hand, space within a broch was limited, though the inhabitants of the surrounding villages (see below) may have been able to gather inside at need, if not their cattle. Not all brochs seem to have had wells or cisterns with access from inside the broch (though the existence of such a well is possible in Gurness), which would have made withstanding a prolonged siege difficult. Therefore, it is argued, brochs were more likely a status symbol of a ruling elite who could command the resources to erect such a building.
A final answer may never be found, and maybe brochs could serve in both functions, as symbol and as final refuge in case of armed conflict.
Midhowe, guard cell in the entrance
Material finds in the brochs and surroundings show that the people of Iron Age Orkney were craftsmen working in stone and bone, bronze and later iron (a centre of iron forging was at Minehowe in Tankerness), and farmers and hunters. They kept cattle for milk and meat, as well as goats, pigs and hens. They also hunted, though venison was not a major part of their diet. Some grain, esp. barley, was grown, and fishing common along the coastlines and rivers. But cattle seems to have been their measure of wealth.
Orkney coastal landscape (view from the Brough of Birsay)
Trade routes – mostly by sea – extended to the rest of the British Isles and probably beyond to the coasts of Scandinavia and the continent. Among the items found in Midhowe (and some other sites like Minehowe) are artefacts of Roman origin, like terra sigillata and bronze fibulae. Paulus Orosius’ tale about Orcadian chieftains submitting to the Emperor Claudius in AD 43 (Historiae adversum paganos, written ca. 385-420, long after the events) can be discarded as source. The first direct contact with Romans may have taken place when Agricola’s fleet circumnavigated Scotland in AD 84. But those items were most likely obtained by trade with southern Britain.
Gurness, remains of the surrounding village
There are two different types of broch, those that stood alone, and those surrounded by villages. The latter type is more frequent on Orkney; both Gurness and Midhowe have villages. The village surrounding the Broch of Gurness is a particularly extensive one. The village at Midhowe may have been built after the broch, but that is now questioned. In both cases, the villages are protected by additional outer walls.
The houses were partly built into the ground; they must have been pretty dark and crowded in winter. I could not find any information about the number of people who lived in those villages; maybe a realistic estimation proves impossible anyway.
Midhowe, house in the village
The development of centres like the broch and village systems points at a change in society from scattered farms to a more stratified society with a leader – likely a leading family – and dependent people who settled close to the broch. This cluster would offer better safety, but also allow the chieftain to draw upon the resources of the people under his 'rule' or what it might be called. Building brochs would need many hands. Did their impressive size enhance the power only of the leader, or of the entire local society? We probably will never know.
Gurness, view out of the entrance to the village remains
We know little about the way those 'kernels of society' interacted. It has been suggested that there was some sort of high chief who held ruled over a group of broch leaders, but alternatively, the defensive structures of the broch and village complexes may have developed due to local feuds and / or as territorial claims, and a 'broch community' was the common unit. I think the latter is the more likely scenario.
The sea was an important part in life of Iron Age people of Orkney and northern Scotland, as the location of the brochs at the coast shows (also, that way they did not take up precious fertile soil further inland). We know that trade and fishing played a role; operations involving larger fleets have been discussed, but are not deemed likely.
Gurness, broch with village remains and outer walls in the foreground
Both Gurness and Midhowe were excavated in 1929/1930; Gurness by J.S. Richardson (who rarely left his base in Edingburgh to visit the site), Midhowe by G. Callander and Walter Grant. At that time, archaeologists were more interested in artefacts than in the construction of the brochs themselves. More excavations were done in the 1980ies, and research of the brochs is going on today, including modern methods like models and computer animations.
Gurness, view from village across the Eynhallow Sound towards Midhowe
The brochs were abandoned around AD 100. In some cases, the villages were re-used at a later time (for example the shamrock house at Gurness which dates to the 4th or 5th century and was built into the remains of the village, using the old stones). The last visitors who may have used the old settlements were the Vikings who left behind a grave at Gurness.
Often the old structures were later used as quarries, which contributed to the damage of brochs and villages. Over time, the villages filled with debris and earth and were grown over with grass, so that only the remains of the brochs are visible.
View to Midhowe (with the modern sea wall) from the distance
Sources
Noel Fojur: The Brochs of Gurness and Midhowe – The official souvenir guide. Historic Scotland, 2008.
Essays on the Orkneyjar Website; essays on the Odyssey Website; summary of a lecture by Dr. Dimitris Theodossopolous held on June 12th, 2020, via The Caithness Broch Project.
¶ June 14, 2020
Brochs are quite frequent in northern Scotland; the remains of some 500 can be found on Orkney, Shetland, the western isles, and Caithness on the Scottish mainland down to the Great Glen. Further south, stone brochs are almost nonexistant. But few are as well preserved and impressive as the Broch of Gurness on the Orkney Mainland and Midhowe Broch on the island of Rousay.
The first essay about the brochs of Gurness and Midhowe will deal with the historical and socio-cultural context of the brochs, while further posts will have a closer look at the buildings themselves. Illustrations are from both brochs.
The outer defense walls and dykes of Midhowe have partly collapsed or are bridged, but some local farmer found a new way to defend the building: The way leads some hundred metres across a meadow which had been freshly fertilised with slurry. I spent an hour cleaning my shoes in the evening. But it was worth some muck. Visiting its twin on the other side of the Eynhallow Sound, the Broch of Gurness, turned out to be less of an adventure.
Midhowe and Gurness are two of several brochs that once lined the shores of the Eynhallow Sound, but most of the others have been collapsed into heaps of stone, were slowly eroded by the sea, or are still buried under grass covered mounds.
Those brochs were built between 600 BC and 100 AD; the one of Midhowe dates to the later centuries BC, the Broch of Gurness to about 400 BC. They were in use at least until the first century AD, and may have been reused in the the 4th to 6th century AD.
A broch is a circular drystone structure. The word derived from Old Norse borg which means 'fortification' (see also German Burg = castle). The same root can be found in the word ‘borough’.
The brochs developed out of the stone built roundhouses that were common in northern Scotland since the Bronze Age (in the south, roundhouses were mostly built of timber).
Those buildings were usually between five to ten metres high; sometimes even higher (the broch at Mousa on Shetland still rises to 13 metres). They usually have double walls with a staircase running inside the cleft to access the upper floors. The single entrance was a door on ground level, often with additional protections like double gates with a passage and guard chambers. Windows are seldom found, but the thatched roof had a louver.
The interior of the ground floor level consisted of a central hearth (a feature already found in the Neolithic settlement at Skara Brae) and a series of chambers along the wall which were partitioned off by stone slabs. Since the interior floors were made of timber, nothing remains to tell us the exact layout of the upper floors, but it seems that they were usually not partitioned. A smoke hole in the centre – which was also used to smoke meat and fish – went through all storeys.
The exact structure of the upper floors is still discussed since no timber features remained. In some cases, they may have been galleries overlooking the central hearth rather than complete storeys.
It took architectural skills and engineering knowledge to erect those double walled structures. The base is wider to carry the weight of the stones, and the double walls not only offer space for a staircase, but were additionally stabilised by insertion of horizontal stone lintel slabs connecting both walls at intervals. That way, a broch could be built higher. The builders needed knowledge about stress and pressure of higher walls to achieve a balance. The roofs were thatched, probably in a domed layout to allow the water to run off. Stone was not used for those domes (other than in the – much lower– cairns).
The brochs across northern Scotland and the islands are built to a similar design. This has led to the theory of traveling master craftsmen who took up commissions for building brochs by chieftains who wanted a fashionable abode. This theory has recently been confirmed by Dr. Dimitris Theodossopolous, Lecturer of Architectural Technology and Conservation at the University of Edinburgh, who specialises in broch architecture. Makes you wonder where they learned their craft and if there was some sort of centre, a school of broch building somewhere. As far as I could find out, there are no examples of less well built 'test' versions of brochs (like it is assumed for the Bent Pyramid).
Sometimes broch walls did collapse, though. Midhowe is an example – it has been repaired by putting stone slabs against the wall as additional buttresses.
It had been assumed that there was an inherent weakness in the construction that led to damage during the use over time, but Dr. Theodossopolous thinks it more likely that the damage was caused by geological shifts. Coastal erosion can lead to a minimal sinking of the rocks some distance inland, and such a small shift would be enough to lead to cracks in the drystone walls which would then widen with the inflow of rainwater and frost. He demonstrated the stability of a broch in a model where the collapse of a part of the wall only happened when he destabilised the basis.
Today, the landscape of Orkney consists mostly of meadows, heather and some bogs, with almost no trees. But once the islands were covered by dense forests of hazel, birch and willow on the lower levels; the hills were covered by open woodlands, meadows and heath. Human activities and climate changes led to a significant decline in forests in the late Neolithic / Chalcolithic (3,500 BC) – which is the reason stone was used as building material in increasing amounts.
During the Bronze Age, the temperature dropped, while at the same time the rainfalls increased, which led to a spread of peat bogs and heath at the cost of farmland. By the middle of the Bronze Age, the fertile soil concentrated in the low parts of the islands, and by 600 BC, Orkney looked pretty much like today (except for the modern buildings), with the same wet and windy weather.
It is assumed that the climate change and decrease of farmland led to a change in society and perhaps to a time of unrest as well, since the patches of fertile land were contested. We don’t know much about the structure of society at the time, but it is likely that the people were organised in tribes or clans, led by a chieftain. Weaponry – together with other items – changed from bronze to iron, which may have had an effect on society.
The question whether the brochs were defensive structures or monuments of some sort is still discussed.
Brochs would have stood out in the landscape as monuments, but there are defensive structures like additional outer walls and dykes as well. And the broch walls itself would have been almost impossible to break with the technology of the time. Another argument if favour of defenses are the elaborate entrances laid out to control who entered the broch. Though no broch shows traces of armed conflict, like a burnt layer or delibarate destruction.
On the other hand, space within a broch was limited, though the inhabitants of the surrounding villages (see below) may have been able to gather inside at need, if not their cattle. Not all brochs seem to have had wells or cisterns with access from inside the broch (though the existence of such a well is possible in Gurness), which would have made withstanding a prolonged siege difficult. Therefore, it is argued, brochs were more likely a status symbol of a ruling elite who could command the resources to erect such a building.
A final answer may never be found, and maybe brochs could serve in both functions, as symbol and as final refuge in case of armed conflict.
Material finds in the brochs and surroundings show that the people of Iron Age Orkney were craftsmen working in stone and bone, bronze and later iron (a centre of iron forging was at Minehowe in Tankerness), and farmers and hunters. They kept cattle for milk and meat, as well as goats, pigs and hens. They also hunted, though venison was not a major part of their diet. Some grain, esp. barley, was grown, and fishing common along the coastlines and rivers. But cattle seems to have been their measure of wealth.
Trade routes – mostly by sea – extended to the rest of the British Isles and probably beyond to the coasts of Scandinavia and the continent. Among the items found in Midhowe (and some other sites like Minehowe) are artefacts of Roman origin, like terra sigillata and bronze fibulae. Paulus Orosius’ tale about Orcadian chieftains submitting to the Emperor Claudius in AD 43 (Historiae adversum paganos, written ca. 385-420, long after the events) can be discarded as source. The first direct contact with Romans may have taken place when Agricola’s fleet circumnavigated Scotland in AD 84. But those items were most likely obtained by trade with southern Britain.
There are two different types of broch, those that stood alone, and those surrounded by villages. The latter type is more frequent on Orkney; both Gurness and Midhowe have villages. The village surrounding the Broch of Gurness is a particularly extensive one. The village at Midhowe may have been built after the broch, but that is now questioned. In both cases, the villages are protected by additional outer walls.
The houses were partly built into the ground; they must have been pretty dark and crowded in winter. I could not find any information about the number of people who lived in those villages; maybe a realistic estimation proves impossible anyway.
The development of centres like the broch and village systems points at a change in society from scattered farms to a more stratified society with a leader – likely a leading family – and dependent people who settled close to the broch. This cluster would offer better safety, but also allow the chieftain to draw upon the resources of the people under his 'rule' or what it might be called. Building brochs would need many hands. Did their impressive size enhance the power only of the leader, or of the entire local society? We probably will never know.
We know little about the way those 'kernels of society' interacted. It has been suggested that there was some sort of high chief who held ruled over a group of broch leaders, but alternatively, the defensive structures of the broch and village complexes may have developed due to local feuds and / or as territorial claims, and a 'broch community' was the common unit. I think the latter is the more likely scenario.
The sea was an important part in life of Iron Age people of Orkney and northern Scotland, as the location of the brochs at the coast shows (also, that way they did not take up precious fertile soil further inland). We know that trade and fishing played a role; operations involving larger fleets have been discussed, but are not deemed likely.
Both Gurness and Midhowe were excavated in 1929/1930; Gurness by J.S. Richardson (who rarely left his base in Edingburgh to visit the site), Midhowe by G. Callander and Walter Grant. At that time, archaeologists were more interested in artefacts than in the construction of the brochs themselves. More excavations were done in the 1980ies, and research of the brochs is going on today, including modern methods like models and computer animations.
The brochs were abandoned around AD 100. In some cases, the villages were re-used at a later time (for example the shamrock house at Gurness which dates to the 4th or 5th century and was built into the remains of the village, using the old stones). The last visitors who may have used the old settlements were the Vikings who left behind a grave at Gurness.
Often the old structures were later used as quarries, which contributed to the damage of brochs and villages. Over time, the villages filled with debris and earth and were grown over with grass, so that only the remains of the brochs are visible.
Sources
Noel Fojur: The Brochs of Gurness and Midhowe – The official souvenir guide. Historic Scotland, 2008.
Essays on the Orkneyjar Website; essays on the Odyssey Website; summary of a lecture by Dr. Dimitris Theodossopolous held on June 12th, 2020, via The Caithness Broch Project.
¶ June 14, 2020
