According to early Irish legend, this site has deep roots in ancient history. The story tells of Cormac Cass, King of Munster in the second century, who was wounded in the head during his victory at the Battle of Knocksouna, where he defeated and killed Eochu Abhradruadh, King of Ulster. Following the battle, Cormac was brought to Duntryleague where a fort was specially constructed around a natural spring. The wounded king’s bed was positioned between three stone pillars, giving the site its name “dun tri liag” or “fort of three pillar stones”. Despite receiving skilled medical care and having water continuously splashed on his head from a bowl, Cormac died and was buried in a subterranean chamber within the fort.

The site’s importance continued through the centuries, with historical records showing that King Brian Boru strengthened Duntryleague in 1002 during his campaigns. By the 16th century, the Burke family of Castleconnell were claiming rents from the area, and in 1655 the estate passed from Jo. Cantwell to Hugh Massy. The Massy family held the property through turbulent times; Hugh Massy junior documented how the Irish partially burned the site, though he managed to save the outbuildings and several turrets. The violence of the period is further illustrated by Hugh Massy’s 1701 will, written whilst he was “in danger of death, occasioned by a wound received from Edw. Moore, of Knockhorden”.

Archaeological interpretation suggests the fort may have been purpose built on the southwestern slope of the mount specifically to enclose the healing well for Cormac Cass, possibly as an extension to an earlier hilltop fortification. Some scholars believe this could be the same earthwork that lies immediately east of Duntryleague church and graveyard, though centuries of destruction have made definitive identification challenging. The site represents a fascinating blend of myth and documented history, where ancient Irish legend intersects with medieval and early modern historical records.