Ua Conchobair, Conchobar Máenmaige (‘of Máenmag’) (d. 1189), son of Ruaidrí, overking of Connacht and claimant to the high-kingship of Ireland, belonged to the Síl Muiredaig dynasty. His father, Ruaidrí Ua Conchobair (qv) (d. 1198), was high-king of Ireland; the identity of his mother is unknown, but apparently he had fourteen brothers or half-brothers and several sisters. His siblings included Donnchad (slain 1199), Áed O'Connor (qv) (slain 1233) and Tairdelbach (d. 1239). Another member of his immediate family was Conchobar ‘ua nDiarmata’ (or ‘ua Diarmata’), who on balance is more likely to have been a fosterling of the Uí Diarmata (around Athenry, Co. Galway) than a grandson of Diarmait. He is described as a bráthair (literally ‘brother’, although the term is often used more loosely) of Conchobar Máenmaige; his father is named as Ruaidrí (ALC) or Cormac (AU). In any event, it seems he was part of the family, whether through blood or fosterage. Conchobar's wife is not identified, but he had at least one son, Cathal Carrach.
Conchobar rose to prominence in the years immediately following the assertion of lordship over Ireland by King Henry II (qv). In 1173, when English forces under Raymond le Gros (Raymond fitz William (qv)) launched an offensive on Munster, Conchobar was appointed by his father as commander of Connacht forces in the east and south of Ireland. In this capacity he supported Domnall Mór Ua Briain (qv), king of Thomond, in a counter-offensive, which destroyed the English castle at Kilkenny and crushed reinforcements sent by the vice-regent Strongbow (Richard de Clare (qv)) at Thurles in 1174. Six years later, he uncompromisingly asserted his father's rule in Connacht when he slew the sub-king of Uí Maine, Conchobar Ua Cellaig, along with his son and a number of kinsmen.
In 1183 Conchobar Máenmaige succeeded to the sovereignty of Connacht when his father Ruaidrí went into religious retirement. It seems that he did not feel bound by the terms of the treaty of Windsor (1175), to which his father was party, and in 1184 he joined with Ua Máelshechlainn of Clann Cholmáin in attacking an unnamed English castle in Co. Meath. Perhaps his rejection of terms with the English prompted his father to stage an attempted return to power; in 1185 Ruaidrí secured the assistance of Ua Briain and plundered western Connacht, bringing that district at least temporarily under his sway. Conchobar and his son Cathal Carrach faced a major crisis, as the struggle against his father merged into a greater conflict, known to historians as the ‘war of the rígdamnae’ (those eligible for the kingship), when his uncle Cathal Crobderg Ua Conchobair (qv) and his ‘brother’ Conchobar ‘ua nDiarmata’ rebelled against him. Eventually, Conchobar Máenmaige won the struggle, drove his father out of Connacht, and proceeded to extend his influence beyond the Shannon. Having taken some English mercenaries into his service, he launched a punitive attack on Ua Briain, who sued for peace and formally submitted.
Subsequently, Conchobar Máenmaige received submissions from several other Irish kings and gave generous stipends to each. These included Mac Carthaig of Desmond and Ua Ruairc of Bréifne, in addition to Ua Máelshechlainn and Mac Duinn Shlébe, who retained rump kingdoms in Westmeath and western Down, respectively, after the English conquests of Mide and Ulaid. Such widespread recognition doubtless lent credibility to his claim to be high-king of Ireland. In 1187 he led an expedition into Westmeath and sacked the English castle at Killare, capturing great booty. The following year, a retaliatory Anglo-Norman invasion of Connacht was guided by the rebellious Conchobar ‘ua nDiarmata’. Having cut a swathe in a north-westerly direction as far as Drumcliff, Co. Sligo, the invaders were repulsed by Conchobar Máenmaige and pursued through Coirrshliab (the pass of the Curlew Mountains), suffering heavy losses. His achievement in maintaining the integrity of Connacht, albeit at the cost of recruiting and endowing a number of English mercenaries with land, was tacitly acknowledged by Gerald (qv) of Wales, who advised that Connacht be placed under tribute rather than colonised.
In 1189 Conchobar Máenmaige was assassinated by a group of disaffected nobles (including several of his kinsmen) at the instigation of Conchobar ‘ua nDiarmata’. The latter was slain shortly afterwards by Conchobar Máenmaige's son, Cathal Carrach (qv). The provincial kingship was assumed by the youngest half-brother of the deposed Ruaidrí, Cathal Crobderg.