kingdom had been greatly strengthened in the time of his grandfather, Cerball mac Dunlainge, but witnessed brief power struggles within the ruling family during his father's time.

Osraige rendered hostages to Muircheartach mac Neill, prince of Aileach, who was brother-in-law to Donnachad by his sister Dubhdara. He gained several victories over the Leinstermen in (946, 972) and Norse (962), suffering losses in 972 in the region of