Prehistoric Orkney refers only to the prehistory of the Orkney archipelago of Scotland that begins with human occupation. (The islands' history before human occupation is part of the geology of Scotland.) Although some records referring to Orkney survive that were written during the Roman invasions of Scotland, "prehistory" in northern Scotland is defined as lasting until the start of Scotland's Early Historic Period (around AD 600).
There are numerous important prehistoric remains in Orkney, especially from the Neolithic period. Four of these remains today constitute a World Heritage Site. There are diverse reasons for the abundance of the archaeological record. The sandstone bedrock provides easily workable stone materials and the wind-blown sands have helped preserve several sites.Wickham-Jones (2007) p. 25. The relative lack of industrialisation and the low incidence of ploughing have also helped to preserve these ancient monuments. In addition, local tradition hints at both fear and veneration of these ancient structures (perhaps inherited from the Norse period of occupation), and these attitudes may have helped prevent human interference with their structural integrity.Moffat (2005) pp. 96–97.Hedges (1984) pp. 11–13, who states that the total number of archaeological sites in Orkney is "around 10,000" i.e. about 10 for every km2.
Prehistory is conventionally divided into a number of shorter periods, but differentiating these various eras of human history is a complex task – their boundaries are uncertain, and the changes between them are gradual. A number of the sites span long periods of time, and, in particular, the distinctions between the Neolithic and the later periods are not clear cut. However, in general, the Paleolithic lasted until the retreat of the ice, the Mesolithic until the adoption of farming and the Neolithic until metalworking commencedMoffat (2005) p. 147. The Neolithic period's extraordinary wealth of structures is not matched by the remains from earlier periods, in which the evidence of human occupation is sparse or non-existent – nor is it matched by remains from the later Bronze Age, which provides a relative dearth of evidence. However, the subsequent Iron Age supported a return to monumental building projects, especially brochs.
Formal excavations were first recorded in the late 18th century. Over time, investigators' understanding of the structures they uncovered progressed—from little more than folklore in the beginning, to modern archaeological science today.
The sites discussed in this article are found on the Orkney Mainland unless otherwise stated.
Paleolithic No evidence of an occupation of Scotland by archaic humans during the Early Paleolithic or Middle Paleolithic has been found.Edwards, Kevin J and Ralston, Ian B.M. "Environment and People in Prehistoric and Early Historical Times: Preliminary Considerations" in Edwards & Ralston (2003) p. 1. For much of the Last Glacial Period, Orkney was covered by the British-Irish Ice Sheet, precluding human habitation. Late Upper Palaeolithic stone tools of the Ahrensburgian culture have been found in Stronsay and Brodgar on mainland Orkney, suggesting the islands have been inhabited around or prior to 8000 BC, perhaps as early as 11,000 BC. At this time, Britain was still connected to the continent via Doggerland. The earliest inhabitants were mobile hunter-gatherers who may have only infrequently visited the islands.
Mesolithic Rising sea levels during the early Holocene saw large areas of Orkney submerge, dividing into two islands by 8000 BC, and resembling the modern archipelago by 6000 BC. During the immediate post-glacial period, Orkney is thought to have been heavily wooded with hazel, birch and willow, with lesser amounts of birch and scots pine.
The very limited archaeological record of this period provides scant evidence of Mesolithic life – in Orkney in particular and in Scotland north of Inverness in general. "Lithic scatter" sites at Seatter, South Ettit, Wideford Hill, Valdigar and Loch of Stenness have produced small polished stone tools and chippings. A charred hazelnut shell, recovered during the excavations at Longhowe in Tankerness in 2007, has been dated to 6820-6660 BC."Hazelnut shell pushes back date of Orcadian site" (3 November 2007) Stone Pages Archaeo News. Retrieved 6 September 2009. However, there is no evidence to suggest whether or not these sites were in year-round occupation and no Mesolithic burial sites have been uncovered anywhere in Scotland to date.Wickham-Jones (1994) pp. 62–63, 74.Noble (1996) p. 173.Finlayson, Bill and Edwards, Kevin J. "The Mesolithic" in Edwards & Ralston (2003) pp. 122–23.
A recently excavated site on Stronsay has produced a thousand pieces of flint and what may be evidence of a temporary camp. With a tentative dating of 7000 BC or older it may prove to be the oldest settlement site found so far on Orkney.Towrie, Sigurd (20 March 2008) "New Contender for Orkney's Oldest settlement Site" Orkneyjar. Retrieved 16 September 2008.
About 6000 BC the Storegga Slides off the coast of Norway created a tsunami that reached above normal high tides in places. Evidence of widespread coastal inundations from a wave high has been found as far south as Fife and the impact on shore-dwelling mesolithic societies in Orkney would have been considerable.Wickham-Jones (1994) pp. 59–60, 74."The Storegga Submarine Slides" . Fettes.com. Retrieved 5 February 2008.Smith, David "Tsunami hazards" . Fettes.com. Retrieved 5 February 2007.
Neolithic
The assemblage of monumental Neolithic structures in Orkney is without parallel in the United Kingdom, and the Orkney Mainland provides an entire landscape of features from this period. During this time, complex new societies came to the fore that were a radical departure from the earlier hunter-gatherers and which were capable of creating substantial structures. The Neolithic in Scotland lasted from approximately 4000 to 2200 BC and Orkney as a whole has nearly 3,000 identified Neolithic sites all told. British archaeologists have often interpreted this era as having two distinct phases; the Earlier Neolithic dominated by regional styles of pottery and architecture followed by a relatively abrupt change into the Later Neolithic characterised by new traditions found throughout the British Isles that incorporate structures on a grander scale. In the Orcadian context, there are definite developments during the Neolithic, but the changes are gradual and tend to build on earlier ideas rather than appearing to form two distinct periods."Death and re-birth" Scotland.org. Retrieved 30 August 2008."Scotland: 4000-2200 BC Neolithic" worldtimelines.org.uk Retrieved 23 August 2008.Noble (2006) pp. 128-31.
The great Orcadian Neolithic monuments were constructed almost a millennium before the sarsen stones of Stonehenge were erected.The sarsens of Stonehenge were erected c. 2300 BC (see "Stonehenge – Forever a mystery" English Heritage. Retrieved 27 September 2008). The Stones of Stenness on Orkney date from the fourth millennium BC, perhaps as early as 3400 (see "Stones of Stenness Circle and Henge" Historic Scotland. Retrieved 27 September 2008). At one time it was believed that this flowering of culture was essentially peripheral and that its origins were to be found to the south on mainland Great Britain. However, recently discovered evidence shows that Orkney was the starting place for much of the megalithic culture, including styles of architecture and pottery, that developed much later in the southern British Isles.Cookson, Clive (10 January 2014) "Science: Orkney – hot spot of the Stone Age". Financial Times. London. Retrieved 18 January 2014.
Early dwellings and chambered cairns
Knap of Howar Neolithic farmstead is probably the oldest preserved house in northern Europe. Situated on the island of Papa Westray (which may have been combined with nearby Westray in the early Neolithic), the farmstead consists of two adjacent rounded rectangular thick-walled buildings with low doorways linked by a passageway. This structure was inhabited for 900 years from 3700 BC but was evidently built on the site of an even older settlement. Unstan ware pottery pieces were found on the site, which was only discovered in the 1920s when this part of the coastline was exposed by gales and tides.Wickham-Jones (2007) p. 40.Armit (2006) pp. 31–33."The Knap of Howar" Orkney Archaeological Trust. Retrieved 27 August 2008.
The Barnhouse Settlement is a cluster of at least fifteen buildings, including one that may have been used for communal gatherings, occupied between 3200 and 2950 BC. The design of the houses, which were built above ground level, includes a central hearth, recessed box beds and stone dressers. There is a network of stone drains leading to a common ditch."The Barnhouse Neolithic Settlement" . Orkneyjar. Retrieved 16 September 2007.Wickham-Jones (2007) pp. 25, 39.Armit (2006) pp. 38–40. Pottery of the grooved ware type, flints and stone tools have been found, as well as three flakes of pitchstone thought to have come from the Isle of Arran.Scottish Archaeological Research Framework (ScARF) 2020. Case Study: Grooved ware at Barnhouse, Orkney. Accessed April 2022.
Skara Brae consists of ten clustered houses and is northern Europe's most complete Neolithic village. Occupied between 3100–2500 BC the houses are similar to those at Barnhouse, but they are linked by common passages and were built into a large midden containing ash, bones, shells, stone and organic waste. Only the roofs, which were probably supported by timber or whalebone, would have been visible from the outside. In each case the stone dressers were erected so that they dominated the view on entering the house through the low doors and there are elaborate carvings of unknown meaning on some of the stones in the houses and passages. A variety of bone beads, pins and pendants and four carved stone balls were also discovered at the site, which was only revealed after a storm in the winter of 1850 ripped away the grass from a covering sand dune. The existing ruins mostly belong to a secondary phase of building with the foundations of the first phase largely hidden from view.Clarke (2000) pp. 1, 11–15, 23."The Heart of Neolithic Orkney" . Historic Scotland. Retrieved 5 September 2007.
There are two main types of chambered cairn on these islands: the Orkney/Cromarty type with a burial chamber approached through a low passage and usually divided into "stalls" by upright stone slabs, and the Maeshowe type (see below), which is a later development with a cruciform layout and an elongated passage.Noble (2006) pp. 103, 115, 118.There are a variety of sub-types including "Bookan", "Tri-partite" and "Hybrid". See Hedges (1984) pp. 80–92.