Ogham is an alphabet used in Ireland and parts of Britain roughly between the fourth and seventh centuries, most often to record a person's name and ancestry in the genitive case, so that a stone reads something like "of X, son of Y, of the tribe of Z". What makes this particular stone unusual is not the inscription itself, but the circumstances in which it was found and the purpose to which it had been put long before anyone read it again.

In 1838, workmen building a field boundary across a low rise in the Dunloe Castle demesne broke into a souterrain, an underground stone-lined passage of the kind built in early medieval Ireland, typically for storage or refuge. This one had been roofed with nine stone slabs, six of which turned out to bear ogham inscriptions. A seventh inscribed stone stood upright inside the passage, propping up one of the larger roof slabs that had cracked in antiquity. Bones and skulls, at least some of them reputedly human, were found inside. The community that built the souterrain had evidently gathered these stones from somewhere nearby, stripped them of whatever commemorative function they once served, and pressed them into use as structural material. The stone now standing by the road measures 1.48 metres high and up to 0.3 metres wide; its inscription, read by the scholar R.A.S. Macalister in 1945, remains well preserved. In 1940 the Office of Public Works removed all seven stones from the souterrain and re-erected them close to the road. The underground structure was filled back in and nothing of it is visible at the surface today. The stones themselves, displaced twice over, have ended up in a tidy row in the open air, a long way from wherever they first stood.