Archaeological fieldwork comprising geophysical and topographical survey was carried out in late August 2010 with funding kindly granted by Meath County Council.
While there is undoubtedly a wealth of archaeology all along the ridge of the Hill of Slane, especially in the vicinity of the extant Graveyard and College – which is likely to have been the location of the original monastic foundation established by St. Erc in the 6th century – we decided to focus our efforts in the beginning was the great mound or motte hidden in the woodland to the west of the ruins.
There were a number of reasons for doing this. There are historical references to the construction of the motte, which is an earthwork castle rather than a stone castle, established along with a borough by Richard le Fleming in 1170. He established another motte on top of the main passage tomb at Knowth. He was granted the lands around Slane by Hugh de Lacy, Lord of Meath whose capital and stronghold was at Trim. We know from The Song of Dermot and the Earl that this was ‘Un mote’ – a motte castle – at Dumhach Sláine. The word dumhach usually refers to a burial mound and the mound. From the Dindsenchas we learn that Sláine, king and judge of the Fir Bolg, died and was buried on Druim Fuar in a great mound called Dumha Slaine (CELT 2005, Poem 77). Thus, it seems certain that the first castle at Slane was built overlying an important prehistoric site close to the medieval parish church. On the SE side of the large enclosure surrounding the motte there is another smaller enclosure, c.25m in diameter defined by a low bank without an accompanying ditch. This smaller enclosure is clearly earlier than the large enclosure surrounding the motte as it is overlain by the larger enclosure. The lidar imagery of the area makes this relationship particularly clear.
The immediate vicinity of the motte is interesting. The motte itself is steep-sided and measures 7.8m high with a summit measuring 20m N-S by 23m E-W. Low stone walling is evident around the summit edge, especially on the N side. The motte is c.45m wide at the base and is surrounded by a 4-5m wide ditch up to 2m deep, partly rock cut, especially along the SE side. The motte stands centrally within a circular enclosure c.163m in diameter. This is well-defined along the S and SW side as a bank with an outer ditch, but this gives way from the NW to the NE side to a simple terrace while to the E and SE it is a low bank. This is not a feature of a classic Anglo-Norman motte-and-bailey and is likely to significantly predate it. The enclosure is almost perfectly circular. On the SE side of the enclosure, there is another smaller enclosure, c.25m in diameter defined by a low bank without an accompanying ditch. Although it is difficult to classify with certainty without further geophysical survey or excavation, it is possible that this is a ring-barrow, a burial monument dating to the Bronze (c.2,500-600 BC) and Iron Ages (c.600-400 AD).
The line of this smaller enclosure is clearly cut by the larger enclosure surrounding the motte and is thus earlier. The arrangement of monuments here on the Hill of Slane bears striking similarities to another monument c.5km away to the NW at Mountfortescue. Here there is another large circular enclosure, c.164m in diameter. Centrally placed within this enclosure is a flat-topped mound, c.12m in diameter and c.1m high. Adjacent to the enclosure is a ploughed-out ring-ditch (a small Bronze- or Iron Age burial monument) visible only on some aerial photographs. Additionally, The Hill of Slane lies within clear site of another very important barrow cemetery (probably Bronze- or Iron Age in date), Slieve Breagh, which lies c.6km to the N and just a few hundred metres from the monument at Mountfortescue.
The Hill of Slane also overlooks the nearby Brú na Bóinne World Heritage Site which was a centre of huge significance especially during the Neolithic period (c.4,000-2,500 BC). Many passage tombs around Ireland are constructed in very visible locations on top of prominent hills and dominate their local landscapes. The Hill of Slane commands the view along the River Boyne from as far away as Drogheda where another famous mound, similarly categorised as a motte castle, stands at Millmount. Intriguingly, Millmount has an associated mythology which explains that the mound is the burial place of Amergin, the first poet in Ireland and there is some speculation that this monument may have started out as a passage tomb.
Thus, we have significant indications that there is likely to have been prehistoric activity on the Hill of Slane, possibly involving the construction of a passage tomb and probably involving the construction of Bronze Age or Iron Age barrows. We wanted to explore this possibility as a starting point for the Hill of Slane Archaeological Project.