Career
Mac Suibhne was a Galllowglass who fought for the Earl of Clanricarde in south Connacht. The family resided at Rath Glas, and were descendants of Domnall na Madhmann Mac Suibhne (fl 1419). The Annals of the Four Masters give his obituary under the year 1586:
Hugh, the son of Owen, son of Donnell, son of Owen, son of Donnell-naMadhmann Mac Sweeny, Chief Constable of Clanrickard, died.
And the person who then departed was a soldier in stature, and a hero in valour.