Ua Ruairc, Áed (d. 1087), son of Art Uallach and overking of Connacht, belonged to the dynasty of Uí Briúin Bréifne. His father Art Uallach was one of four kings of his dynasty to reign as overking of Connacht between 956 and 1102, his reign being from 1030 to 1046, when he was killed by Cenél Conaill, enabling his Síl Muiredaig rival, Áed in Gaí Bernaig Ua Conchobair (qv), to take the kingship. Áed had at least one brother (or half-brother); he was named Niall and was slain (1047) by Ua Conchobair. In 1067 Áed overthrew his brother's killer in the battle of Turloch Adnach and laid claim to provincial suzerainty. It seems that several of his dynasty held lesser kingships under him: his uncle, Donnchad Ua Ruairc (slain 1084), is styled ‘king of eastern Connacht’ in his obit in the Annals of Tigernach (Tigernach Ua Bráein (qv)), while other kinsmen, Domnall (slain 1078) son of Tigernán and a son (slain 1085) of Domnall, were rulers of Bréifne or Conmaicne.
An ambitious overlord, Áed sought to extend the authority of his dynasty south-eastwards into Brega. Specifically, he sought to dominate Gailenga (a petty kingdom which leaves its name on the barony of Morgallion, Co. Meath), and made his presence felt at Drogheda. It is possible that he was behind the killing (1076) by local Gailenga dynasts of Murchad king of Mide, a nephew of Conchobar Ua Máelshechlainn (qv). In any event, he seems to have exploited the opportunity created by his neighbour's murder.
Before long, the threat Áed posed to Mide was so serious that the new king of Mide, Máel-Sechnaill Bán son of Conchobar, felt obliged to seek assistance from Tairdelbach Ua Briain (qv) (d. 1086), the Dál Cais overking of Munster. Áed's base-kingdom of Bréifne was subjected to raids by the Munstermen in 1079 and again the following year. About this time, he boldly appointed Cennétig Ua Briain, whose faction of Dál Cais was excluded from power, as king of Gailenga so that he might frustrate the designs of the powerful Tairdelbach. In 1084 at Drogheda Áed met Donn Slébe son of Eochaid, overking of Ulaid, who had led a hosting southwards. Áed's acceptance of a stipend from the Ulster ruler implied support for the latter's efforts to challenge Ua Briain interests for political supremacy. That summer the Munstermen made an expedition into Mide, but Ua Ruairc's forces went behind them and raided into north Munster, burning several fortresses and churches and carrying off considerable booty. It seems that another Bréifne force under the command of Áed's uncle Donnchad headed further south, but was intercepted at Móin Cruinneóice (near Leixlip, Co. Kildare) and routed, Donnchad himself and Cennétig Ua Briain being among the slain.
Ultimately, the Ua Briain interest brought about the fall of Áed: his leading Síl Muiredaig rival, Ruaidri na Saide Buide Ua Conchobair (qv), who was married to Mór, daughter of Tairdelbach Ua Briain, went on the offensive against him. In 1087 Áed, along with many of his nobles, was killed at the battle of Corann and the overkingship was retaken by Síl Muiredaig. Most of the later kings of Bréifne descended from Áed's brother Niall.