The Annals of Inisfallen record that Eladach son of Dunlang was killed in a battle in Muskerry in 828.
The preponderance of Norman personal names is probably due to the influence of such families as the Cogans, the overlords of Muskerry in the 13th century.
All of these 0 Healys must have joined Lord Muskerry in the 1641 rebellion since the entire group (described as 'gentlemen') were declared outlaws in 1643, together with John of Castlemore, Thomas of Mashanaglass and Donogh 0 Hialighy of Ballyburden (near Ballincollig), 'a doctor of Physic'.