Ogham is an early medieval Irish writing system in which letters are rendered as groups of notches and scores cut along the edge of a stone, typically recording a personal name and lineage. That these particular stones were repurposed in this way, set into a souterrain, an underground stone-lined passage or storage chamber used in early medieval Ireland, means that the inscriptions themselves were already ancient, possibly forgotten, when the structure was built.

The souterrain was discovered in 1838 by workmen constructing a field boundary across a slight rise in the Dunloe Castle demesne. It was roofed by nine slabs, six of which carried ogham inscriptions, and one of the larger inscribed stones had cracked in antiquity and was braced by a seventh, which stood upright within the passage. Human bones and skulls were also found inside. In 1940 the Office of Public Works removed all seven stones from the souterrain and erected them beside a nearby public road; the chamber was subsequently filled in and no surface trace of it remains. The stone catalogued as KE065-078006 stands 1.3 metres high and up to 0.45 metres wide. Its history as a lintel cost it much of its text: the inscribed face was damaged before reuse, removing all vowel-notches and scores from that surface. The scholar R.A.S. Macalister, working in 1945, read the surviving edge scores as a fragmented sequence, ...MC...GE...M..Q...D...E, though later examination found that even parts of this partial reading were no longer clearly visible, including what appears to be a forfid, a supplementary symbol used in later ogham to represent sounds not covered by the original alphabet. The stone has since been documented as part of the Ogham in 3D project run by the School of Celtic Studies at the Dublin Institute for Advanced Studies, which produces high-resolution digital models of inscribed stones across Ireland.