Weis' "Ancestral Roots. . ." (175:2), King of Munster, 1023. On pilgrimage to Rome 1064, and d. the same year. Kelley's "The Ancestry of Eve of Leinster" (The Genealogist, 1980) XII:17.

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 probably 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. Teige O'Brien had a son, Turlough, who was a prince of courage and ability. He resolved to avenge the death of his father, and to dethrone Donogh. At that time, Diarmid, King of Leinster, was a rival of Donogh for the sovereignty of Ireland, and Turlough entered into an alliance with him against his unnatural uncle. Turlough was aided also by the king of Connacht. The final battle between King Donogh of Munster and Turlough took place in 1063. Donogh was defeated. He was most unpopular with his subjects because of Teige's murder. Thoroughly disheartened and worn out after a sad reign, he went on a pilgrimage to Rome where he died the following year, after doing penance. He took the crown of Ireland, which Brian Boru had worn, and presented it to the Pope.10