A datestone is a small but unusually direct piece of historical evidence: a carved inscription, usually set into a wall at the time of construction, recording who built a structure and when. Most such stones remain in place, ageing quietly alongside the building they once announced. The datestone from Coolnamuck tower house in County Waterford took a different path. Sometime in the nineteenth century, it was lifted from the tower house where it had sat for roughly two or three hundred years and moved to nearby Coolnamuck House, separating the inscription from the building it was made to commemorate.

The stone records that a tower house at Coolnamuck was built in 1588 by Geraldus Wall and his wife Catherine Quenneforde, whose name also appears in the anglicised form Commerford. Tower houses were fortified residences of a type common across late medieval Ireland, typically built by landowning families as a combination of home, status symbol, and defensible stronghold. The Wall family, who were among the Norman-descended dynasties that had settled in Munster, were building at a moment of considerable turbulence in Elizabethan Ireland, which gives the 1588 date a particular weight. The relocation of the stone in the nineteenth century was not unusual for the period; demesne improvements and country-house renovations frequently involved the gathering of older fragments as curiosities or ornamental features, with little concern for keeping objects tied to their original contexts.