A 7thc. foundation, although much of the remaining fabric of the church dates to the 15thc. A number of Romanesque fragments are kept in a stone store at the site. Two further carved stones are now held in the Fermanagh County Museum. These are a rectangular limestone block carved with a ecclesiastical figure, and a corbel/section of cornice carved with an exhibitionist figure. In 1894 the stone carved with the ecclesiastical figure was recorded as standing in the graveyard 'about ten yards to the north east of one of the walls of St Ronan's church' (Dagg 1894, 265). The carving of the exhibitionist figure was discovered built into the core of the S wall of the Church (Hickey 1976, 66).

In 2003 two carved stones forming a Crucifixion panel were rediscovered during building work to the gateway to Aghalurcher graveyard. (Stalley 2009)

The monastic site was founded in the 7thc. by St Ronan. No records of the site during the 11th–12thc. survive. The Annals of Ulster record for 1447 states that: 'This year a ribbed vault was put by Thomas Mag Uidhir junior, namely, king of Fir-Manach, on the church of Achadh-urchaire in honour of God and SS Tighernach and Ronan. And it was he that built the eastern gable of the church for the good of his own soul, and so on.' (Annals of Ulster, 159).

The fragments of architectural sculpture from Aghalurcher are sufficient to indicate the presence of a 12thc. building at the site.

The chevron voussoirs appear to have formed the outer order of a portal of at least two orders. The closest parallel for the chevron type, at Devenish, on loose pieces also from a portal context, has additional floral decoration in the spandrels. The closest parallel for the interlace fragment is also found in the Lough Erne Basin on one of the head capitals at Kilmore, and on a fragment from Maolaoise's House at Devenish.

The discovery of the carved fragments set into the gateway raises a number of intriguing questions. When was the arch into the graveyard constructed and why were the sculptures deliberately concealed? Did the blocks belong to a free-standing structure or were they fitted into the walls of the Romanesque church? There are also questions of style, in particular the extent to which the work relates to other Irish carving.

The fact that only one face of each block was carved suggests that the blocks were set into the walls of the 12thc. church. The fact that the stone is not heavily weathered lends credence to the view that the sculpture belonged to the interior rather than the exterior of the building. The church at Aghalurcher was rebuilt in the later Middle Ages and it is remarkable that the carvings were retained in the Gothic reconstruction. The gateway into the graveyard is likely to have been erected in relatively modern times, yet somehow the blocks managed to survive.

The placing of figures below a Crucifixion recalls arrangements on the 12thc. high crosses at Tuam and Glendalough. The analogies with the Market Cross at Tuam are especially close, not least since Christ wears a crown (an indication of triumph and eternal rule). He is also furnished with a triangular loincloth, as at Tuam. The presence of the suppadaneum or footrest gives a strong hint that the Crucifixion was copied from a bronze original; in fact, the carving of the Crucifixion could have been modelled on a processional cross. As for the figure style, the elongated bodies and the character of the faces fit quite comfortably into the context of Irish Romanesque sculpture; there are obvious similarities with the bronze figures on the shrine at Lemanaghan (Offaly) (note in particular the large, rather flattened ears). The style of the figures also recalls the bishop’s head already known from Aghalurcher, which may well have been made by the same sculptor. The function and context of the sculptures remain a mystery, the only known example of Romanesque carving used in this particular way. The identification of the two figures is also puzzling: were they figures from Christian history or major patrons, perhaps of the church at Aghalurcher?