A plaque fixed to the structure records that it was erected at the expense of County Kilkenny in August 1818, under the oversight of Humphrey Hartley J.P., and that its middle arch was destroyed in 1922 and subsequently restored in 1925 by the county surveyor R. F. Bowen. Those dates alone span a turbulent period in Irish history. But the more interesting question is what lies beneath, or rather within, the stonework itself, because the extent to which any earlier medieval fabric survives in the present bridge remains unknown.

The documentary evidence for a bridge at this crossing reaches back considerably further than 1818. The Ormond Deeds, a collection of records relating to the powerful Butler dynasty of Kilkenny, refer in 1538 to a property transaction in which Piers Butler, Earl of Ormond, granted two messuages in the town of Callan to a carpenter named Thomas Howleghan, one of them described as lying by "the great bridge." A further deed from 1577 mentions a property on the hill of Callan at the north end of the same great bridge. The phrasing in both cases, "the great bridge," suggests something well-established and locally significant rather than a modest ford crossing. The Down Survey map of 1655 to 1656, a large-scale cartographic project carried out under Cromwellian administration to record forfeited Irish lands, depicts the bridge with what appears to be a castle or gatehouse structure on its southern side, a detail that points to a once-fortified crossing of some consequence. Cutwaters, the angled projections built into bridge piers to divide the flow of water and reduce pressure on the structure, are a feature of the present bridge and are consistent with medieval bridge-building practice, though that alone proves nothing about age.

The bridge sits between Upper Bridge Street to the south and Lower Bridge Street to the north, so the road layout of Callan has long oriented itself around this crossing. Whether the stone beneath the 1818 reconstruction preserves anything of the medieval "great bridge" is a question the fabric of the structure has not yet answered.