Circular buildings represent the vast majority of Iron Age structures in Scotland, (as elsewhere in Britain but in contrast to the near Continent). They can vary in size from less than 7m to approaching 20m in diameter, although ‘modest‘ proportions (c. 8m across) appear most commonly, and it is hard to imagine that all served the same role in Iron Age settlements (Harding 2009, 275). Although culturally specific, it is of interest that Crone (2000) interpreted the 8m diameter Early Historic house at Buiston crannog as the home of a wealthy farmer, supported by the evidence from early Irish documents. While wary of extending such evidence into a pre-Roman Iron Age context, the site illustrates the potential dangers of linking status to size in a simplistic manner. Care is also needed with regard to how dimensions of timber roundhouses have been identified from surviving remains in plough-truncated lowland contexts, because there has been a tendency to underestimate diameters by failing to take into account non-earthfast elements of the structure, such as turf walls (e.g. Harding 2009, 273).
‘Substantial‘ or monumental buildings are covered below (see 5.4); however in this context, it is now widely recognised that no simple equation can be drawn between monumental structures and social status. It is nevertheless widely considered that occupants of monumental houses were displaying identity, prestige and independence (Hingley 1992, 14-17; Armit 1997c, 27) but this remains an assumption based on current models of Iron Age society. Egalitarian vs. elite models for explaining substantial houses are discussed by Hingley (1992, 40-1) as having relevance at different times and different places. In some areas and at some times ‘substantial houses‘ seem to represent the only archaeologically detectable settlement form; for example the Atlantic roundhouses of North Uist and Barra are much discussed (Armit 1997a and b, 2002; Sharples and Parker Pearson 1997), and there the equation of such substantiality representing an elite is, perhaps, not so easy to articulate. A similar argument has been made for crannogs of the central highlands (Cavers 2006, 399) on the basis that there is nothing to indicate high-status, with artefacts and ecofacts suggesting a distribution of large disaggregated roundhouses supporting the interpretation that local society did not reflect social relationships through architecture (although see above about problems of identifying the character of buildings on crannogs).
These examples show the need for and importance of locally-based models of the evidence for and context of substantial houses.
There are a range of recurring ground-plans of timber roundhouses in much of southern and eastern Scotland, which are sometimes known by the short-hand reference to their salient structural feature as of ring-groove, post-ring and ring-ditch construction. But it is unclear what these distinctions signify, particularly as, in many areas they are in use over the same long timespan and are demonstrably not chronologically exclusive 'type-fossils', and, indeed, are not uncommonly found as elements of the same settlement. An attempt was made to model possible ethnic, functional or social variations for the post-ring houses and ring-ditch houses juxtaposed at Kintore, Aberdeenshire. Here the excavators argued for the occupants of ring-ditch houses having a dominant relationship with their post-ring counterparts (Cook and Dunbar 2008) an argument that has not found general agreement.
The indigenous adoption of exotic architecture has often been seen as an indication of origination and use by high-status occupants. The so-called ‘southern brochs‘ may be an excellent of this - Macinnes‘ model of a network of high-status sites with occupants controlling a prestige goods economy associated with the redistribution of Roman goods is still widely accepted (Macinnes 1984a). More could be done on the background of this innovation – there are other stone structures in the southern Scottish Iron Age, often termed duns (e.g. Stanhope (Peeblesshire), Castlehaven (Kirkcudbrightshire) or Castlehill Wood (Stirlingshire)). How can these be fitted into the model of exotic influence? And how many more such brochs can be anticipated? The Buchlyvie broch was an unprepossessing mound before excavation, while the recently-discovered broch at Castle Craig, Auchterarder gave no hint of any surface presence. Are all southern brochs similar, or should the Galloway ones be seen as an integral part of the Atlantic world, rather than an innovation (Henderson 2007a, 165-66; Cavers 2008, 16-17)? And do they all date to the Roman Iron Age? The lack of Roman finds from some extensively-excavated examples (eg Edinshall; Dunwell 1999) raises some questions.
Structure as an indicator of status
Some have sought to link specific aspects of architecture as evidence of high-status, for example:
- Entrance orientations: the work by Parker Pearson et al. (1996), where differences between broch entrance orientations were linked to status distinctions between the occupants - although much of this has been challenged by Pope (2007) and the measurement of entrance orientations was revisited by MacKie (2010, 104-5 and fig 4).
- Grand entrances / porches: as elements of display, but Harding (2009) has suggested there may be fewer projecting porches than some think, because building sizes have been underestimated by not accounting for non-earthfast wall lines.
- Quality of construction: comparing the apparently poorly constructed Atlantic roundhouse (e.g. at Crosskirk. Caithness; Fairhurst 1984; Ralston 1996, 139) and the visibly well built Atlantic roundhouse (e.g par excellence at Mousa, Shetland) - but does this matter in terms of status of building, and was this quality recognised at the time of construction? Did this matter in terms of the 'status' of the building, and was 'quality' more associated with foreseen duration of use or the nature of indentured labour involved in the construction. Could poorly constructed examples such as Crosskirk be ‘imitations’ of high hollow-walled structures? (based upon comment made by E MacKie in response to the ScARF Iron Age workshop).
- Commissioned construction: were there 'professional' broch-builders that might indicate the wealth and status of those that commissioned construction? The case is not proven, but simple structures at least were probably built by local communities (Armit 2003, 77-78; Romankiewicz (2011) argues for a locally-based construction of all such structures).
There are some cases where recurrent differences in the character of material assemblages of artefacts recovered from different types of structure appear to reflect real social differentiation, thought the topic has been under-studied. This is most evident when looking at the distribution of exotica, particularly Roman artefacts occurring on non-Roman settlement sites (Macinnes 1984a, Hunter 2001), but trends can also be detected in the distribution of non-Roman artefacts (Heald and Jackson 2001, Hunter et al. 2009). However, the taphonomy and circumstances of deposition also need to be taken into account - there may be a wider range of material in some types of structure because material was deliberately deposited as part of recurrent foundation or closure acts (e.g. Hurly Hawkin ; Taylor 1982, Hunter 1997. 115-116 and 122).
The Sequence of Northern Stone Structures and its Subdivision
The broch has long been a dominant feature in the study of the Scottish Iron Age, and its classification and development has excited much debate. Some regions (notably Orkney) appear to show a typologically clear developmental sequence from fairly simple, though sometimes substantial, roundhouses (at e.g. Early Iron Age structures at Bu, Quanterness, Calf of Eday, Pierowall Quarry, Howe, through increasing architectural complexity (including intramural chambers and galleries, upper staircases, inner wall-face voids, scarcement ledges) to a state of broch or broch-like appearance. Howe, in particular, appears to show a clear sequence of increasing architectural complexity and scale over a prolonged period of time from the Early Iron Age through the Middle Iron Age; although there are problems with comparing poorly preserved wall foundations of earlier truncated roundhouses with later, better-preserved structures on the site. In the Western Isles there are still no clear parallels for the simpler Early Iron Age roundhouses that are found in the Northern Isles and whether or not this is a genuine absence requires more work..
Armit‘s terminology of Simple and Complex Atlantic Roundhouses (Armit 1991, and revisited in Armit 2005b) is an attempt to rationalise into a related typological sequence the numerous sites known mainly from non-intrusive survey of settlement mounds that reveals only limited architectural detail. This also aimed to bridge the regional gap between things called brochs in the north and things called duns in the west, the terminological difference hiding many clear similarities (here Harding’s split of duns into those which could be roofed (dun-houses, less than 20m) and those which could not is very useful). In recent years years there has been a move away from detailed analysis and debate concerning the minutiae of the architectural detail and consequential definition of broch status (but see Armit 1997 a and b, Sharples and Parker Pearson 1997) This move has, for better or for worse, been in favour of attempting to address more intimate scales of human activity and practice, seeking to define the functionality of brochs; often post-structuralist, postprocessual approaches have been adopted, highlighting social and symbolic factors.
The diffusionist paradigm utilising architectural and artefactual typologies has been, and continues to be, very influential in Atlantic Iron Age studies. Further reassessment of, and sustained innovative studies of, material culture are required in order to assess and where necessary update the assumptions that have been inherited from previous work (see Atlantic Architecture and Portable material culture section below). Connectivities within the Atlantic zone have been stressed in recent synthetic reviews (Cunliffe ***; Henderson ***), and the mechanisms and meanings of this deserve further work.
How do lowland brochs fit into their settlement landscapes, especially in relation to other stone architecture?
Are substantial houses individual domestic units or do they reflect the incorporation of multiple activities or groups of people under one roof - latterly disaggregated into separate structures (e.g. the Atlantic Roundhouses vs. cellular settlements of the Atlantic north and west or substantial timber roundhouses vs. scooped settlements in south-east Scotland).
Is the variation in house size and construction simply about the availability of timber (Cook and Dunbar 2008, 13), or were other social factors responsible?
Can settlement types be equated with a social 'class' - which has led to the suggestion that occupants of brochs were either elites or landowning farmers, depending upon the location or the researcher.
What range of activities took place on crannogs?