That deliberate elevation, modest as it is, gives the site an oddly commanding quality; and the earthworks visible in the surrounding field suggest this was never just a church in isolation, but the anchor of a wider settlement whose full extent has long since sunk back into the grass.

The parish, known variously as Aharney, Aghteyr, Agheteart, and several other spellings across the centuries, appears in the record from at least the thirteenth century. For much of the medieval period it was the property of the Augustinian Priory of Inistioge, a few miles down the Nore. After the Reformation the rectory passed through a succession of lay lessees: Richard Butler of Ferns took it in 1541, James and Edward Cuffe in 1576 to 1577, and Henry Davelles in 1584. By 1615, a Regal Visitation found the rectory worth five pounds and noted that both the church and chancel were under repair. Local tradition, recorded by the historian William Carrigan in 1905, held that during the Williamite and Jacobite wars the building was re-roofed and pressed back into use as a Catholic chapel, and that the original oak roof timbers stayed in place until late in the eighteenth century. The structure itself is built from roughly coursed limestone rubble, with walls ninety centimetres thick, a bellcote at the apex of the west gable, and corbels inside that once carried a gallery. The original chancel arch, round-headed and 2.4 metres high, was eventually blocked up and replaced with a plain doorway when the chancel was converted into a mortuary chapel for the Mountgarret family. That conversion apparently stripped out much of the earlier detail, though one survival is notable: a piscina, the small basin used for rinsing liturgical vessels, set within a chamfered pointed niche and fitted with a fluted bowl, which Carrigan described as a very handsome piece of Gothic design. The chancel also retains a wall monument dated 1634 and a graveslab dated 1694, both tucked into the angles of the chapel walls.