Augaire (d. 1024), son of Dúnlaing and overking of Leinster, belonged to the Uí Muiredaig lineage of the Uí Dúnlainge dynasty. During the reign of his father Dúnlaing (qv) (d. 1014), king of Uí Muiredaig and briefly overking of the province, the interests of his dynasty had surfaced at Glendalough and at other north Leinster ecclesiastical centres. It is probably significant that in the last year of Augaire's reign a raid by Uí Fháeláin dynasts on Kildare drew a response from Uí Muiredaig. Augaire's immediate predecessor as overking of Leinster was his brother Donn-cuan, who was slain in treacherous circumstances by the ambitious Donnchad (qv) son of Gilla-Pátraic, king of Osraige at Leighlin in 1016. Having succeeded to the kingship, Augaire made strenuous efforts to secure the position of his dynasty within northern Leinster. He secured support from the Síl Cormaic lineage of Uí Chennselaig and from the dynasty of Uí Bairrche, but had to contend with rival claims from the king of Osraige. In the years that followed, Augaire's own dynasty and those allied to it became locked in a protracted vendetta with the ruling lineage of Osraige.
Meanwhile Augaire endeavoured to assert his authority over the Norse kingdom of Dublin. In 1021 he severely defeated Sitriuc Silkbeard (qv), son of Amlaíb (Óláfr) Cuarán (qv), at Delgany, Co. Wicklow. This battle appears to mark a turning-point in relationships between the Norse of Dublin and Uí Dúnlainge, which had suffered severely during the lengthy period of Dublin ascendancy. It may have been about this time that Augaire's sister Máel-corcra was given in marriage to Amlaíb son of Sitriuc; there are signs that a modus vivendi was arrived at, and the two dynasties feature increasingly as allies. Augaire, it seems, also pursued an expansionist policy in southern Leinster, where the failure of Uí Chennselaig dynasts to resolve a protracted succession dispute provided a convenient opportunity for intervention.
The first of two intrusive Uí Muiredaig kings of south Leinster, Máel-mórda (qv) son of Lorcán, emerged in the reign of Augaire. It is scarcely coincidental that Augaire and his protégé Máel-mórda were together in the former's house at Dubloch when both were slain (1024) by a rival dynast of the Uí Fháeláin lineage. Augaire's immediate successor in the Uí Muiredaig kingship seems to have been his brother Domnall, who forcibly imposed an abbot on Glendalough (1031). Two other brothers, Dúnchad (or Donnchad), who was slain in 1037, and Murchad (qv), who fell in battle in 1042, aspired to the overkingship of Leinster. Later kings of the Ua Tuathail line, however, were descended from the above-mentioned Donn-cuan or from yet another brother, Tuathal.