The brochs, great stone towers of Iron Age Scotland, are famously puzzling. Who inhabited this strongholds (if habitations they were)? New fieldwork at the broch of Dun Vulan, on South Uist in the Western Isles, prompt reappraisal of the geographical and social context of the brochs, by developing untrapped sources of social evidence.
The most enduring and impressive domestic buildings of the northern European Iron Age are the brochs of Scotland. These dry-stone towers dominate the archaeological landscapes of western and northern Scotland, and many still survive to heights between 4 and 13 metres. Their walls, between 3 and 5 m thick, contain staircases, chambers and galleries and they enclose circular or sub-circular living areas normally about 10 m in diameter. These were almost certainly roofed and supported one or more upper floors.
Not surprisingly, these structures have attracted considerable antiquarian and archaeological interest and 'broch-ology' is almost an intellectual pursuit in itself. The history of broch interpretation is a microcosm of broader developments in archaeological method and theory. Their form and shape have been the subject of typological and evolutionary classifications (Scott 1947; Graham 1949; Lethbridge 1952; Young 1964; MacKie 1965a); their origin has been explained as the result of migration or invasion (Childe 1935; Mackenzie 1972; MacKie 1965a; 1983), or as defences against sea raiders (Curle 1927; Anderson 1883); their distribution has encouraged studies of catchment and territory (Scott 1947; Fojut 1982; Armit 1988; 1992); their architecture invites complex statistical and spatial analysis (Martlew 1982; Hedges 1987; Foster 1988a; 1988b; Armit 1992: 101-8); and they have been subject to one of the earliest post-structuralist applications of contextual archaeology (Barrett 1981).
When writers have referred to 'the problem of the brochs' (Scott 1947; Lethbridge 1952; MacKie 1983; Swanson 1984) they have invariably been concerned with the function and purpose of these seemingly out-of-place monuments. In the windswept climate of western and northern Scotland, why should anyone construct dwellings of such tall and massive proportions? And why should they later abandon them? They appear not to have been refuge towers since deep accumulations of domestic refuse have been recovered from many (Fairhurst 1984: 179). Nor were they simply the castles of exploitative Iron Age barons on the evidence of their density and distribution (Fojut 1982; Armit 1988: 1992). The general consensus is probably best summed up by Fairhurst who suggests that the average broch was '. . . a homestead as well as a place of refuge . . . something in the nature of a fortified farmhouse perhaps in continuous occupation by the headman's family.' (1984: 181-2).
Recent research by the University of Sheffield's Department of Archaeology and Prehistory on Barra and South Uist in the Western Isles has led to a further re-evaluation of why brochs were built. The SEARCH project (Sheffield Environmental and Archaeological Research Campaign in the Hebrides), begun in 1987, has been investigating long-term changes in settlement and environment from the Neolithic to the post-medieval period [ILLUSTRATION FOR FIGURE 1 OMITTED]. One of the main research themes of the project has been the development of the Iron Age landscape, focused on rescue excavations of a broch, Dun Vulan [ILLUSTRATION FOR FIGURE 2 OMITTED], and a wheelhouse, Kildonan III (Zvelebil 1990), on South Uist's west coast. A programme of survey and excavation has led to further rethinking of the context of brochs within their social landscapes and to reinterpretation of their significance and purpose.
Definitions and dates
Much of the recent discussion on the dating of brochs has revolved around the definition of such structures. For some a broch has to be 'a round, drystone, tower-like building with a specialized series of architectural features which include the characteristic high, hollow wall containing superimposed galleries' (MacKie 1965: 100; 1983: 118). Others consider that brochs should be subsumed within a broader category of Atlantic roundhouses, thick-walled, roofed monumental buildings which includes brochs, duns, semi-brochs and galleried duns (Armit 1991: 182; 1992: 18). The earliest of these Atlantic roundhouses are a group of thick-walled simple roundhouses excavated in Orkney, dating to 800-400 BC (Armit 1991: 186-9). Armit considers that broch towers and wheelhouses belong to the succeeding period between 400 and 200 BC (including the clustered village settlements of Orkney and Caithness); he sees brochs continuing to be used in the period 200 BC-AD 200 (1991:201-2). According to MacKie, brochs (Armit's 'broch towers') do not occur until much later, after 100 BC, being the products of southern British migrants retreating from the Belgic expansion, who improved on the local building traditions of simple Atlantic roundhouses (MacKie 1965; 1982; 1983). Brochs continued to be built at least into the 1st century AD and possibly into the 3rd and 4th centuries in some areas (MacKie 1989).
Our own view recognizes the broad category of 'Atlantic roundhouses' but identifies an unequivocal category of brochs as defined by MacKie. We would also agree with the date in the 1st century BC suggested by MacKie for the appearance of the broch. Armit (1991) has exaggerated the significance of a few early dates from sites such as Dun Bharabhat (Harding & Armit 1990), The Howe (Ballin Smith 1994) and Crosskirk (Armit 1991) which do not satisfy the definition of brochs. The larger number of dates available from recent excavations at Dun Vulan in South Uist (Pearson & Sharples forthcoming) and Scalloway in Shetland (Sharples forthcoming) provide no support for the argument that brochs were constructed prior to the 1st century BC. However, we would reject the argument for southern …