EMAP_Progress_Reports_2009_2.pdf - The Heritage Council

Offaly
Clonmacnoise, Co. Offaly
Early Medieval Ecclesiastical Enclosure.
Grid Ref: N011308 (20110/23080)
SMR No: OF005-004; OF005-058.
Excavation Licence: E0558; 99E0715
Excavation Duration/Year: July – August 1979; 1990 – 1998; 1997 – 1998; 1999-
2000.
Site Director: R. Ó Floinn (National Museum of Ireland); H. King (National
Monuments and Historic Properties Service, Dúchas); A. O’Sullivan (Management
for Archaeology Underwater Ltd.) & D. Boland (Management for Archaeology
Underwater Ltd.); D. Murphy (Archaeological Consultanct Services Ltd.)
The monastery is situated on the east side of the Shannon at a crossing point of the major
east-west route-way, the Slighe Mhor. The site is linked with St. Ciaran, who may have
founded the earliest church there c. A.D. 545. By the ninth century, the site had fallen within
the control of the Clann Cholmain dynasty of the Southern Uí Neill. This period saw a
concentrated phase of patronage at the site including the construction of the cathedral and
the erection of the ‘Cross of Scriptures’ in the early-tenth century. The ruins of the
ecclesiastical settlement include the cathedral, seven churches, two round towers, three high
crosses, a holy well and the largest collection of early medieval cross-slabs in Ireland.
The discovery of Hiberno-Scandinavian coins within the monastic enclosure instigated a
rescue excavation under Raghnall Ó Floinn in 1979. The hoard consisted of three pennies
(including one silver penny) of Hiberno-Scandinavian date, a bronze ingot and a fragment of
a gold earring deposited c. AD. 1065-1095. A stone-lined drain and a hearth were also
excavated, and these revealed a jet bracelet fragment and a bone pin, as well as several
industrial remains (crucible fragments, a fragment of tuyère, fragments of a clay mould,
industrial slag (4kg), and a furnace bottom).
Rescue excavations were conducted in the garden of the round tower in 1989 in advance of
the construction of a visitor centre. Four phases of activity belonging to the early medieval
period were discovered. The earliest phase was represented by stakeholes, furnace waste
and industrial fragments. A habitation surface, with stakeholes and an occupation surface,
was situated above this layer. A path was also discovered composed of gravel. Another
habitation layer with stakeholes was confined to the eastern half of the area. Preliminary
analysis suggests that these stakeholes may represent the remains of circular huts. Part of a
two-sided comb and a bone trial piece with interlace and fretwork patterns were found in a
dark humic layer; and a large quantity of animal bone was also recovered.
Underwater archaeology along the Shannon uncovered the location of the bridge mentioned
in the Annals of Clonmacnoise in A.D. 1158. Seven pairs of posts were found along the
northern bank, and longitudinal timbers, which may represent the side supports of the bridge,
were also discovered. These timbers were dendrochronologically dated to A.D. 804. Further
excavation of the bridge in 1997 revealed that the bridge originally measured 120m long and
5m wide, and was likely to be about 10-13m in height. The bridge was built of 25 pairs of
vertical oak posts. It appears to have been a single-phase structure (no evidence for repairs
was discovered) and would not have lasted much longer than 40-50 years.
The ‘new graveyard’ at Clonmacnoise had been opened in the mid-twentieth century, without
prior archaeological investigation. An ogham stone was discovered during grave-digging in
1990, which persuaded the Office of Public Works to authorise a limited excavation.
Excavation carried on in this area for the next eight years and revealed much about the
domestic and industrial aspects to the monastery.
At least five separate domestic structures were discovered during the course of these
excavations. The earliest evidence of occupation on the site is a series of postholes in the
natural sandy soil of the esker ridge, and these have been interpreted as the remains of a
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