The Crannóg: Early Medieval Field Monument

By Liam Loftus

A crannog is “an artificial island constructed by driving piles into the mud of the lake and building it up

with layers of peat, brushwood, stone, branches and other material until it rose above water level.”1 Its

artificial foundations are kept in place by a retaining

ring of close-set vertical piles, forming a palisade

around the site. The name crannog derives from the

Irish cránn meaning ‘tree’ and is thought to refer to

the timber settlement itself rather than the

foundations on which it is erected or the palisades

that surrounds it. Crannogs are distributed

throughout Ireland but are highly concentrated “in the north midlands and south Ulster, along the

drainage systems of the rivers Shannon and Erne and in the isolated lakes of the drumlin zone.”2 Today

crannogs appear as small wooded islands at the edges of lakes or as tree-grown or grassy hummocks in

areas that have undergone drainage. Alternatively crannogs may be entirely submerged due to rising

water levels and the gradual compaction of the

crannog material.

The waterlogged nature of crannogs

allows for the excellent preservation of its

organic remains which can be used today for

dating purposes. O’Sullivan (1998) suggests that

Irish crannogs may not have been an indigenous

development but instead the concept of crannog-building may have been “introduced from Scotland

into Ireland in the late sixth century AD.”3 Dendrochronology tends to support this theory, indicating a

distinct phase of crannog activity around 600AD. The sheer amount of crannogs built during this time

1 M.J. O’Kelly (1995) Early Ireland. Cambridge University Press, Melbourne, p. 298. 2 M. Ryan (Ed.) (1994) Irish Archaeology Illustrated. Country House, Dublin, p. 120. 3 A. O’Sullivan (1998) The Archaeology of Lake Settlement in Ireland. Royal Irish Academy, Dublin, p. 101.

Fig. 1 – Wooded crannog surrounded by pasture land

Fig. 2 – Isolated Irish lake dwelling and dug-out canoe

indicates major changes in Irish society “which made the construction of these well-defended

homesteads a necessity.”4 Whether it was sudden increase in surplus wealth or the result of political or

social upheaval, something “destabilised early Irish society to the extent that defended settlements

became vital.”5 Either way there was a

surge in crannog-building during the

fifth and sixth centuries AD which

indicates that their construction was a

common response to particular

environmental or social conditions.

Crannogs often contain several

occupational layers which indicate a

long history of occupation and reoccupation. O’Sullivan (1998) acknowledges that crannog-builders

“made use of earlier features. Mesolithic, Neolithic and Bronze Age lake settlement mounds were also

often the location for Early Historic crannogs, the elevated platforms over the marshy ground or water

providing a useful base to start from”6 Unfortunately, the

multi-phase nature of most crannogs means that there is no

definite date for the beginning of crannog construction.

Subsequent phases obscure the initial occupation layer of

many crannogs, while dendrochronological evidence may

represent ‘only one particular woodworking phase and not

necessarily the original construction phase.’7 However what we do know is that crannogs continued to

be occupied and reoccupied well into the early seventeenth century despite their functional change at

4 N. Edwards (1990) The Archaeology of Early Medieval Ireland. London, Routledge, p. 36. 5 A. O’Sullivan, The Archaeology of Lake Settlement in Ireland, p. 132 6 A. O’Sullivan, The Archaeology of Lake Settlement in Ireland, p. 133 7 Ibid., p. 133

Fig. 3 – Craggaunowen crannóg, Co. Clare

Fig. 4 – Connemara crannóg

different times. Crannogs were often used as strongholds and continued to be reused as refuges for the

poor or hideouts for outlaws well into the eighteenth and nineteenth centuries.8

According to Edwards (1990) the construction and composition of crannogs varies considerably

as their composition was dependent upon the material available. Their method of construction also

“seems to have varied according to the depth of the water and whether it was an extension of a natural

islands or a totally artificial one.”9 Although ‘true’ crannogs are predominantly timber structures,

crannog-builders often utilized natural features on the lake bed in order to give them greater stability.

For example, Ballinderry No.2 (Co. Offaly) is an extension of a natural island, whereas Ballinderry

No.1 is an entirely artificial construction that required much more substantial foundations. These

foundations were composed of massive split-oak timbers, laid side by side and consolidated by a band

of small piles that were hammered into the lake mud. Peat, brushwood and other organic matter were

used to pack the foundation. A timber palisade provided both an enclosing framework for the crannog

make-up as well as an additional measure of protection. The timber ‘crannog proper’ was built on top

of this foundation. Stone were sometimes used in the foundation and in the west of Ireland where

timber may have been scarce many crannogs were built entirely of stone. Wooden piles were often

found outside the main palisade of many crannogs and these

may have served as a deterrent for hostile boats or simply as

breakwaters to prevent erosion of the crannog foundations by

wave-action. Many palisades had an east-facing entrance and

some may have had a gate-tower for added protection. Many

crannogs were built in the centre of small lakes and could only

be approached from dry land by a causeway or by boat.

8 O’Sullivan (1998) states that crannogs “were used as fishing stations, as dog pounds, as illicit stills for making poitín and as ‘kail gardens’ for producting vegetables.” (169) 9 N. Edwards, The Archaeology of Early Medieval Ireland, p. 38

Fig. 5 – Crannóg with a well-made stone causeway

Excavations at Ballinderry No.1 have revealed traces of a landing stage which may have been used for

boat navigation and storage.

Traditionally scholars have interpreted the social and economic role of crannogs in terms of

power, defensiveness and social display. It is generally thought that crannogs were the settlements of

wealthy nobles or powerful kings. The excavation of several large crannogs like Lagore (Co. Meath) or

Moynagh Lough and “the quality of the finds recovered from such sites, as well as the amount of

labour involved in their construction, would appear to indicate that they were mainly aristocratic

dwellings.”10 However, it is clear from archaeological surveys that most crannogs were essentially

small island dwellings quite unlike Lagore or Moynagh Lough, occupied at various times by different

people who were not necessarily of high social status. Indeed many crannogs have produced relatively

modest material assemblages that indicated that most activity was focused on cattle herding and arable

crop production along the lakeshore.

Lakes were ideal places for human settlement. They provided food, water and raw materials.

They were surrounded by rich sloping grasslands and

had valuable access to route-ways through the early

Irish landscape. Any crannogs that were built on these

lakes must have played an important economic role an

agricultural society. O’Sullivan (1998) suggests that at

a time when pastoral farming was of great social and

economic importance, crannogs were “positioned at

particular parts of lakes to control prime pasture on the

neighbouring drylands.”11 The discovery agricultural

tools and large quantities of animal bone on many

10 M. Ryan (Ed.), Irish Archaeology Illustrated, p. 123 11 A. O’Sullivan, The Archaeology of Lake Settlement in Ireland, p. 144

Fig. 6 – Agriculture tools and weapons found in a crannóg

crannogs suggest farming activities on adjacent dry land. As a result, some associated structures like

ringforts “may not have been settlements but byres and corrals for the protection of the cattle.”12 The

agricultural function of crannogs is supported by a wide selection of well-preserved organic remains at

Lough Eskragh which “established that the inhabitants were primarily farmers, raising cattle and sheep

and cultivating cereals.”13

Many historical sources have identified some crannogs as high-status sites, signifying power

and prestige. Lagore can certainly be interpreted as the island

residences of kings or nobles as the material assemblage

found “is unquestionably impressive and testifies to the high

rank and wealth of some of the people who frequented the

lakeshore.”14 However Lagore also provides abundant

evidence for on-site bronze-working as well as a range of

other domestic crafts such as carpentry, pottery-making, bone-

working, looming and leather-working. This indicates that

many crannogs were not just royal sites, but were also centres

of craft production. Indeed Bofeenaun (Co. Mayo) appears to

have been dedicated solely to the activity of iron-

working, since no traces of domestic activity have been

found. O’Sullivan (1998) suggests that lakeshores

provided “various resources for the metalworker such

as wood for fires, clays for moulds and kilns, and water.

These metalworking sites may also have been usefully

situated by water for travel and communications, or to

12 Ibid., p. 144 13 M.J. O’Kelly, Early Ireland, p. 305 14 C. Newman (2002) Ballinderry Crannóg No. 2, Co. Offaly: Pre-Crannóg Early Medieval Horizon., p. 114

Fig. 7 – Bone motif-pieces from Lagore, Co. Meath

Fig. 8 – Gilt bronze brooch from Lagore, Co. Meath

be at places between territories for trade and exchange.”15 Crannogs can be seen as neutral meeting

places where local kings could attract trade goods into the region and distribute the metalwork and

glasswork through the wider community, in which case “crannogs served as centres for the production

and redistribution of goods, making them significant non-urban markets in the wider settlement and

economic landscape.”16 Craftsmen may have been gathered together on crannogs as a result of royal

patronage or to control trade.

Crannogs are important archaeological sites due to their extensive material assemblages and the

high preservation of their artefactual remains. They provide us with an insight into the social and

economic dimensions of past lives and their long history of use and reuse attests to their continued

importance in Irish society. At different times throughout their occupation there appear to have been

significant differences in the social and economic functions of crannogs. Therefore, it is important to

gain a broader understanding of crannogs, particularly in relation to the wider social and cultural

landscape.

15 A. O’Sullivan, The Archaeology of Lake Settlement in Ireland, p. 95 16 Ibid., p. 141.

Bibliography

Edwards, N., (1990). The Archaeology of Early Medieval Ireland. London, Routledge.

Fredengren, C., (2000). Iron Age Crannógs in Lough Gara. Archaeology Ireland, Vol. 14 No. 2, No.

52.

Fredengren, C., (2001). Poor People’s Crannógs. Archaeology Ireland, Vol. 15 No.4 Issue No. 58.

O’Kelly, M.J., (1995). Early Ireland. Cambridge University Press, Melbourne.

O’Sullivan, A., (1998). The Archaeology of Lake Settlement in Ireland. Royal Irish Academy, Dublin.

O’Sullivan, A., (1998). Crannógs in Contested Landscapes. Archaeology Ireland, Vol. 12 No. 2, No.

44.

Lynn, C. J., (1983). ‘Some ‘Early’ Ringforts and Crannogs’, The Journal of Irish Archaeology, Vol. 1,

pp. 47-58.

Lynn, C. J., (1985). ‘Lagore, County Meath and Ballinderry No. 1, County Westmeath, Crannógs:

Some Possible Structural Reinterpretations. The Journal of Irish Archaeology, Vol.3, pp.69-73.

Newman, C., (2002). Ballinderry Crannóg No. 2, Co. Offaly: Pre-Crannóg Early Medieval Horizon.

The Journal Of Irish Archaeology, Vol. 11, pp. 99-123.

Ryan, M., (Ed.), (1994). Irish Archaeology Illustrated. Country House, Dublin.

Images

Figs. 1, 2, 5, 6, 7, 8 – O’Sullivan, The Archaeology of Lake Settlement in Ireland.

Fig. 3 – http://www.gov.ie/images/photos/CL000363__.jpg

Fig. 4 – http://www.connemaraheritage.com/images/Crannog.JPG