Notes "A New History of Ireland."
After the Battle of Clontarf two of Brian's sons survived--Teige and Donogh. Teige had fought in the battle; Donogh had been absent on a cattle raid, and took no part in the fight. Teige was like his father, and was a favourite with the people, who regarded him as Brian's probable successor; but Donogh was ambitious, and was chosen Ard Righ by his father. Donogh instigated the people of Ely O'Carroll to murder Teige, which they were base enough to do. This Clontarf hero, who had fought to save his country, was slain by his own kinsmen at the instigation of his step-brother; for Brian Boru was married three times.10