Leabhar Clainne Suibhne (The Book of Mac Sween) states that after Áed's death, although his older brother Domnall was the rightful heir, Ánrothán was chosen instead to be king [REF].
The history from Leabhar Clainne Suibhne may be a fabrication that provides the clan with a pedigree connecting them to the Milesian kings of Ireland, although historian W. D. H. Sellar believes this history may be genuine [REF].