It commemorates a Captain St Barbe, a resident of nearby Ballinafad Castle, who was interred there in either 1622 or 1628, the exact year apparently uncertain even at the time it was first noted down. The slab bore an inscription and a coat of arms, details recorded carefully enough to suggest it was once a legible and reasonably substantial piece. Now it is simply gone, or at least unlocatable, which gives it a particular kind of melancholy distinction among memorial stones.

The earliest written record of the burial comes from 1836, when local details were gathered for the Ordnance Survey Name Books, a systematic effort in the nineteenth century to document place names, antiquities, and local tradition across Ireland. The name was set down at that point as Captain St Ware, though this appears to have been a mishearing or copying error for St Barbe. It was George Petrie, the antiquarian and artist who contributed substantially to the Royal Irish Academy's collections, who recorded the slab itself, noting its inscription and heraldry in manuscript. Petrie was meticulous in such matters, which makes the subsequent disappearance of the stone all the more frustrating. Ballinafad Castle, where Captain St Barbe lived, still stands not far away, a planted castle of the early seventeenth century associated with the colonisation of the area during the Ulster Plantation period, which gives some context to the presence of an English military officer in this part of Connacht at that time.