Bran Ardchenn (d. 795), son of Muiredach and overking of Leinster, belonged to the Uí Dúnlainge dynasty. His father Muiredach (reigned 738–60) was a strong ruler whose descendants through Bran (whose sobriquet may be rendered as ‘high head’) later formed the dynastic lineage of Uí Muiredaig, based at Maistiu (Mullaghmast, south Co. Kildare). Bran, who apparently was anxious to reach an accommodation with Clann Cholmáin, the powerful Uí Néill dynasty of the midlands, married Eithne (qv), whose father Donnchad Midi (qv) was king of Tara. Whether or not she was the mother of Bran's sons, Muiredach (d. 818) and Cellach (d. 834), is not recorded.
By the early 780s Bran was a leading opponent of his first-cousin, Ruaidrí son of Fáelán (qv) (d.738), who, as king of the Leinstermen, was struggling to challenge the overlordship of Clann Cholmáin. Dynastic frictions erupted into open conflict when the two cousins joined battle on the Curragh of Kildare (27 August 782). Although Bran had engaged the support of Uí Fhailge and Uí Chennselaig dynasts, he was defeated and captured on this occasion. Nonetheless, Bran succeeded to the kingship (785) on the death of Ruaidrí. There are hints that he had Clann Cholmáin support. It is probably significant that Leinster was spared from Uí Néill agression during Bran's reign, and that Donnchad Midi, king of Tara, hosted to Leinster (794) to assist his son-in-law in curbing Munster ambitions.
It is possible that Bran's marriage-alliance fuelled dynastic rivalries within Uí Dúnlainge; on 6 May 795 he was assassinated along with his wife, being burned to death by the son of a first cousin, Fínshnechtae Cetharderc (qv), at Cill Chúile Dumai (probably in Co. Laois and not Kilcoole, Co. Wicklow, which John O'Donovan (qv) suggested). Bran Ardchenn's sons later featured in Leinster dynastic politics; Cellach reigned as overking 829–34, while Muiredach, who in 805 was promoted to an ephemeral joint-kingship of the Leinstermen by Áed Oirnide (qv), king of Tara, was the ancestor of the later kings of Uí Muiredaig.