Publication Account
Date 2007
Event ID 587320
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/587320
NB13 3 BEIRGH ('Berie', 'Traigh na Berie 1', 'Loch na Berie', 'Riof', 'Reef')
NB/1034 3516
This slightly aberrant ground-galleried broch in Uig, Lewis, stands on flat, marshy ground south of Traigh (‘beach') na Berie and 400m from the shore (visited July 1990). Before excavations began in 1985 all that could be seen was a low, stony, grass-covered mound in which the outer wallface could be traced in places, giving an overall diameter of 16.5m (54.1 ft) [2]. This site is another interesting example of how misleading surface indications can be (see NB13 2 above). The Commission's investigators clearly thought that there was little left, and that the entrance was “quite destroyed” [2]. However the excavation showed that in places the broch wall still stands at least 3.00m (9.8 ft) high under the accumulated silt and rubbish [3, fig. 27].
Excavations have occurred in two spells, from 1985-88 and 1993-95, under the direction of Prof. D W Harding of the Department of Archaeology at the University of Edinburgh. However this account of the work has to be a partial one for several reasons. In the first place the work is unfinished; the primary Iron Age floor inside the broch has not been reached and our knowledge of the beginning of the occupation of this site is therefore almost non existent. At the time of the final revision of this entry (September 2005) there appeared to be no prospect of it continuing. Secondly only vol. 1 of the report has appeared – concerning the structures and stratigraphy found [3] – and this contains very little about the sequence of material culture found. Thirdly, much of the site sequence which was unravelled falls into the late Iron Age, or “Pictish” period, so is not directly relevant to the main themes of this study of brochs. The account here is therefore a summary except for the description of what has been exposed of the broch itself.
1. The structures and stratigraphy
1.1 Introduction
Almost certainly the site was originally on a rocky islet in a loch, now silted up and covered with reeds [3, Plate 1]. The 1957 OS 1 inch map shows a small loch here but the information used was probably out of date even then. A causeway runs across the reedy bog immediately west of the broch (towards the hills) but it seems to be modern and built with looted stones; however it may replace an older one. The site is still extremely wet; at the time of the author's visit the water was standing in the broch almost up to the level of the lintels of the ground gallery – and that must be about 1.5m at least above the primary floor. The water must therefore have risen at least 2m since Iron Age times.
An important aspect of this broch is that the gradual silting up of the loch around it, and the rising of the water level, seems to have been going on since Iron Age times with the result that the earlier levels are waterlogged. If and when these are ever reached, well preserved organic material will doubtless be found, as in the underwater site at Dun Bharabhat (NB13 2). These wet deposits can be seen inside the lowest gallery which is only about half full of debris [3, Plate 51].
The phasing system adopted to describe the history of the site runs, counter-intuitively, from recent to earlier instead of from the beginning to later horizons; the reason of course is that the oldest levels have not yet been uncovered and their number is therefore uncertain. Thus Phase 1 is the latest horizon and eleven more have been defined going back to the building and first occupation of the 'Atlantic roundhouse' or broch (Phase 12). Since the description of the material culture sequence at the site is reserved for another volume the cultural context of this broch and its secondary buildings cannot be adequately described here apart from those few aspects of it which have been published (section 4 below). A simple diagram of the main phases of occupation is in the report [3, figs. 4a and 4b] and the author has attempted another version trying to integrate the site sequence with the local sequence of material culture.
1.2. The broch
It is not altogether clear how the features of the basal storey of the broch have been identified since most of that level is still buried by the unexcavated deposits in the interior. Presumably it was possible to see the intra-mural galleries – and the tops of the doorways from these to the central court – by peering under the lintels of the former. Sometimes the report gives the mis-leading impression that more is known about the primary levels than is the case. For example some readers might easily conclude that the plan of the broch at ground level with the inserted roundhouse is showing the roundhouse floor at its primary level; the plan shows paving and other features which suggest the original floor and which appear to be linked with the roundhouse wall. However we know from the sections [3, fig. 21] that excavation inside the broch has nowhere reached more than about a metre below the level of the scarcement so there must be up to another metre of deposits below the floor level shown. Of course a careful reading of the text (and the sections) reveals this [3, 50] but the plans should have been labelled to make this quite clear.
Broch Level 1 (Phase 12). The main building is a very well preserved, almost ground-galleried broch which still stands to above scarcement level all the way round; the lintels roofing the ground level galleries are in position [3, figs. 15 and 16]. The report [3] is accompanied by a folder which contains large-scale plans of the various superimposed buildings at a scale of 1:75.
Beirgh is a relatively slim-walled structure with overall diameters of 16.7m (54.8 ft) east-west and 17.1m (56.07 ft) north-south [3, fig. 16]. The corresponding internal diameters are 10.2 and 10.7m (33.4 and 35.1 ft) and the average wall proportion (the percentage of the total diameter (d) occupied by the two wall bases on it. (b1 and b2); this can be found with the simple formula: % = (b1 + b2) x 100 / d. A more useful figure – but one more difficult to obtain – would be obtained by working out the proportion of the area of the central court to that of the broch as a whole) would thus be 38.2%. The classic ground-galleried broch Dun Mor Vaul on Tiree has a wall proportion of 42.2% – slightly more massive (NM04 4). The entrance passage faces almost due east and its lintels, including a large and thick outermost one, are in situ; the passage is 3.3m long with built checks for a door 1.2m from the outside. There are several 'niches' in the sides of the passage just below lintel level but any bar-hole and socket for the door-frame are still buried. A lintelled guard cell opens from the left side of the passage, behind the left check.
At 7.30 o'clock is the doorway to an oval mural cell (“Gallery 2” in the report) 2.25 m long and also lintelled. There is a similar doorway to a similar cell at 9 o'clock but in this case the length is 4.1 m. A third doorway at 2.30 o'clock leads to a long gallery which, on the left, extends clockwise back to the cell just mentioned for a distance of some 13.8 m. To the right it leads to the intra-mural stair the first exposed step of which appears after 2.0 m; the rest is still buried so the flight must start much closer to the doorway. Thus at this site, as at Dun Mor Vaul (NM04 4), there is no stair-foot guard cell as such, only a long gallery.
At 4.30 o'clock is the fourth doorway which leads to the same stretch of gallery but behind the stairway; that part to the left of the doorway is called “Gallery 6” for some reason and that to the right – some 2.9m long – is “Gallery 7”. Both Gallery 7 and the anticlockwise end of Gallery 4 are in effect long cells because of short projections from one wall which give the impression of an internal doorway. The entire intra-mural space is roofed with lintels most of which are intact although they do not form an even surface [3, Plates 40 and 41].
Two examples of secondary masonry were found which appeared to antedate the insertion of the roundhouse (below) [3, 54-5 and figs. 25 and 26].
The inserted roundhouse (Phase 10). At some stage a secondary wall 1.0 to 1.5m thick was built against the north half of the inner face of the broch wall; in the southern half the added wall was not continuous, leaving the original wall exposed in places. On either side of the entrance (which evidently remained open, though half full of debris) were two radial piers which create two ”perimeter cells”; that on the right looks like a new guard cell for the passage. The doorways into Galleries 2 and 6 remained accessible although the others – including that to the stair – seem to have been blocked. The occupation deposits of the roundhouse (the deposits of which are still largely un-excavated except in the north-east quadrant [3, 51]). had been sealed in by a layer of laid peat which was the most distinctive horizon in the internal stratigraphy [3, 42]. The text has to be read carefully to find out just how little of these lower levels are known, though the situation is clearly set on p. 56 [3]; the detailed plan of the secondary roundhouse can give the casual reader the false impression that it was completely explored.
Judging from the section drawings [3, fig. 21, etc.] the roundhouse appears to have become partially filled with occupation deposits over a long period, and then with what looks like fallen rubble mixed with soil strata. Some idea of the complexity of the later floor levels can be gained from the excavators’ descriptions [3, 50-1]. On top of these stony deposits, and about level with the broch scarcement, was the peaty horizon noted earlier and on which was built the first 'cellular structure' of Phase 9; this is the start of the occupation of the site in what is termed the Pictish period [3, fig. 13] but these later horizons are not discussed in detail here. Whether Pictland proper really extended so far west from its heartland in the north-east main-land is debatable. They can be studied through the excellent series of plans accompanying the report.
An underground cellar, or souterrain, was inserted into the floor of the roundhouse at a late stage. A single C-14 date was obtained for what was inferred to be later roundhouse occupation – from material resting on the lintels of the ground level gallery which included standard decorated Iron Age pottery [3, 63]. The date is –
GU-4923 1760 +/- 50 bp
which calibrates to AD 220-338 at the 68% confidence level. At least part of the first floor gallery was still intact and roofed when these deposits accumulated because lintels from a higher level were found on them. This implies that the broch was standing to a higher level – and perhaps was still a completely intact tower – when this debris accumulated.
Broch Level 2 (Phase 12). The chamber over the main entrance, opening to the interior, is partly preserved and several courses of its inner part are in position above scarcement level. Its floor (the lintels roofing the passage below) has been exposed [3, Plate 42] and presumably joined the scarcement by means of the innermost lintel, now vanished. Likewise the outer part of the wall presumably formed the outer end of this chamber but this has all disappeared apart from the massive outer lintel (which itself had to be reset in position [3, Plate 35]). This chamber connected with the Level 2 galleries on either side of it [3, fig. 15].
A fine ledge scarcement, some 30cm in width, is on the interior wallface at an unknown distance above the floor [3, fig. 15]. The only gaps in this ledge are at the main entrance (where the bridging lintel has evidently disappeared) and at the Level 1 doorway at 2.30 o'clock where the twin capstones are several centimetres lower than the scarcement. This ground level door is described as “first floor level” [3, 56] which is slightly confusing as the term usually means first raised floor. Presumably there was a low void here over the lower doorway the upper lintel of which (forming the sill of the raised doorway) has disappeared. The excavator says that this raised opening provided the only direct access to the Level 2 gallery, the similar doorway at 3 o’clock (below) being unsuitable because of the stairwell [3, 57]. However the inner end of the chamber over the entrance would have provided much more commodious access.
There is also a gap at 3 o'clock where a doorway in Level 2 leads to a short landing in the stair; a few steps of the second flight survive to its right. Here the sill of the doorway is evidently slightly higher than the ledge. The large-scale plans of the area [3, figs. 14, 15 and 16] does not show all these details but the structures are shown in Plate 44 [3]; the small plan of the area makes all clear [3, fig. 25]. To the left of the pole are the few remaining steps of the second flight of the stair, with a few flat slabs of the landing visible in front of it (a large paving-slab had been exposed here when the photograph in the report was taken). To the right of the pole is the raised doorway to the interior, which emerges there, as noted, slightly above the scarcement.
Most of the lintels flooring the Level 2 gallery (and roofing that of Level 1) are still in position [3, Plates 40 and 41]. As one would expect these are missing immediately clockwise from the stair, obviously to make a stairwell to allow people to go up and down it [3, fig. 15]. Occupation debris had accumulated on these but there was an empty space of varying depth below them, and on top of the still largely unexplored deposits in Level 1 [3, figs. 26 and 27]. The excavator suggests that, before they became the receptacle for midden material, there was a floor of beaten earth on these lintels (which by themselves make but a rough and irregular surface). This implies that the Level 1 gallery was used regularly when the tower was intact.
The first floor gallery meets the chamber above the entrance on both sides to form an unusual “cross-shaped” pattern, the gallery coming from the left widening to a wedge shape as it overrides the lintelled guard chamber below. This situation contrasts with that in many other brochs in which this chamber is either isolated except from the interior or has one gallery connecting with the chamber. Dun Carloway used to be the only obvious parallel to Beirgh here (NB14 1) but Dun Telve (NG81 2) is now known to be another as may be Loch an Duna (NB24 1).
Broch Level 3. There are a few signs that Beirgh had at least three superimposed galleries in its wall. Some lintels fallen from the floor of the third gallery were found lying in the second, and under these slabs was found middle Iron Age midden material resting on the lintels of the ground level gallery. The pottery here was highly decorated and a long-handled bone comb was another find. Presumably this midden material was dumped in the gallery during the roundhouse phase of occupation.
The beginning of the second flight of the stair also implies that there was a third level in the wall, though whether this was an open gallery running round the wallhead or a closed one cannot be determined now. The slimness of the broch wall suggests that it was never really tall.
1.3 The later structures (Phases 9-1)
Very briefly described, the post-Roundhouse occupations inside the ruined or demolished broch (and founded on deep deposits which had already accumulated therein) fall into two groups, the first being a series of 'Cellular structures' (Phases 9-5) which mark a complete change of style from the period of the Iron Age roundhouses. These are unusual buildings in the Western Isles, having what look like a series of irregular, open-fronted cells peripheral to a clear central area. They recall to some extent the 'courtyard houses' found in the late Bronze Age levels at Jarlshof in Shetland (HU30 1) and which have so far seemed to be a phenomenon confined to the Northern Isles. At Gurness (HY32 2) too there is evidence of the very late survival of this type of dwelling.
The 'cellular structures' were followed by another fundamental change of style in which a series of 'Figure of Eight' buildings was erected (Phases 4-1). The inner wallfaces of the first of these were formed of vertical slabs revetted against older midden material; in other words this was partly a dug-out structure, inserted into material already accumulated in the interior of the broch. However some of these slabs rested against the broch masonry, or the secondary facing against this, with an air space behind them. There was a central hearth with a second peripheral fireplace.
The layout of all these buildings is shown, Phase by Phase, on the commendably large-scale and detailed plans [3, figs. 5-11].
Radiocarbon dating: four C-14 dates were obtained for the occupation of the 'Cellular structures' which followed that of the Roundhouse. The calibrated dates AD are given in brackets below each entry, to a 68% level of confidence.
1. GU-4927 1700 +/- 50 bp (ad 150)
(AD 253 – 406)
2. AA-23724 1650 +/- 55 bp (ad 300)
(AD 340 -433)
3. AA-23723 1595 +/- 60 bp (ad 355)
(AD 400 – 542)
4. GU-4926 1580 +/- 60 bp (ad 370)
(AD 411 – 549)
No. 1 comes from the peat layer laid down at the start of this period, so presumably also dates the end of the Roundhouse occupation to the late 2nd or the 3rd century AD. Nos. 2-4 are for samples from the occupation levels and they all fall rather neatly into the late 3rd and 4th centuries. No such dates were obtained for the figure-of-eight buildings but some characteristic artifacts from those horizons are datable (below).
1.4 Artifact dating
A detailed study of the artifacts has yet to be published but some indications of the results are given in the first report [3, 63-7]. A number of unusual artifacts were found in the post-broch 'Cellular phase' occupations and these help both with dating and with assigning the phase to a more general cultural context. Particularly important is the bronze-working debris found dumped mainly in Cell 7 in the earliest of these levels. This included slag, crucible fragments and mould fragments, the last providing the evidence for the artifacts made on site. There were two-piece moulds for undecorated hand-pins (a late form of ring-headed pin) and proto-hand-pins; the former type is usually assigned stylistically to the period from the 5th to the 8th centuries, and the prototype form perhaps to the 3rd and 4th centuries.
The other important find was the mould for a bronze 'doorknob' spear-butt, primarily an Irish phenomenon (although the moulds have only been found in Scotland) and which is usually dated to the 1st and 2nd centuries (Raftery 1982). A recent re-assessment, based partly on the radiocarbon evidence from Beirgh, suggests a slightly later time span, lasting from about the 3rd to the 5th centuries (Heald 2001, 690) (this is important for the later chronology of Dun Mor Vaul – NM04 4).
A fragment of Roman Samian ware dating to the late 1st or the first half of the 2nd century (Drag. 18 or 18/31) was found in a deposit of the late Cellular phase. Clearly it must have been kept on the site for quite a long time after it arrived, and that arrival itself may have occurred some time after it was made. This Roman pottery is found fairly frequently in early broch levels, though rarely in the Outer Isles.
The finds from the 'late Pictish period' with figure-of-eight houses, and their implications for dating, are discussed in some detail [3, 64-7] but need only be alluded to briefly here. An important new artifact is the composite bone comb, several fragments of which were found. Plain pottery is the norm, and crucibles of Laing's Type 8 were also found. Two bronze penannular brooches found are of forms (Fowler's Types G and H) which are thought to date from the 5th/6th centuries and the 7th/8th centuries respectively (Laing 1993) [4, Illus. 6.22]. However they were in reverse order stratigraphically; in other words the earlier levels of the 'Later Pictish period' seem to be dated more accurately by the later brooch.
Sources: 1. NMRS site no. NB 13 NW 3: 2. RCAHMS 1928, 20, no. 69: 3. Harding and Gilmour 2000: 4. Harding and Armit 1990, 94-107.
E W MacKie 2007
...continued in Part 2 (Event ID 1039142).
