The site likely began as a medieval castle, possibly a tower house with a defensive bawn, which served as the old manor house of Callan. This stronghold passed through some of Ireland’s most prominent families; from the descendants of Earl Marshall to the Earl of Ormond in 1391, then to Lord Desart around 1700, and eventually to George Agar, Lord Callan, in the latter half of the 18th century. Local historian Thomas Shelly believed this was the very Butler castle that withstood the Cromwellian siege of Callan in 1650, making it a site of considerable military importance during that turbulent period.

The Down Survey map of 1655-6, drawn by George Marshall and copied by Daniel O’Brien, shows a substantial house within the townland of ‘Whitescourte’, which appears to be Westcourt House and may well have incorporated elements of the earlier medieval castle. Following the death of owner John Galwey in 1793, Lord Callan demolished what remained of the old manor and replaced it with an impressive Georgian mansion. This grand house stood for nearly 150 years until disaster struck around 1940, when a catastrophic fire gutted the building. The house was subsequently abandoned and eventually demolished, leaving only a rubble heap west of the walled garden to mark where it once stood.

Archaeological excavations conducted in 2000 have revealed tantalising glimpses of the site’s medieval past. Archaeologists uncovered scorched mortar and slab flooring that may date to the castle’s earliest phase, along with a substantial wall footing about 1.5 metres wide, complete with a defensive batter and an adjacent fosse, or ditch. These features suggest the presence of a fortified bawn that would have protected the medieval castle and its inhabitants. While the grand houses are gone, their foundations and cellars likely survive beneath the surface, waiting to tell more of their story to future generations of archaeologists and historians.