Ua Máelshechlainn, Conchobar (d. 1073), son of Domnall and king of Mide, belonged to the Clann Cholmáin dynasty of the Uí Néill. A grandson of Máel-Sechnaill (qv) son of Domnall, he was the first member of the family line of Ua Máel-Sechnaill (Ua/Ó Maolsheachlainn; O'Melaghlin; O'Loughlin) to reign as king of Mide, a dignity he retained for forty-three years. His father, Domnall (d. 1019), was abbot of Clonard; his mother, Cacht, was the daughter of a minor noble, Brian Ua Bicin. He had a brother named Flann. Conchobar married Mór, daughter of Ua Conchobair Failge, who was the mother of his sons Murchad (d. 1077) and Máel-Sechnaill Bán (d. 1087), and of his daughter Ben-Midi. His wife Mór, according to the Life of St Colmán of Lynn (Co. Westmeath), took the fortress of Dún na Cairrce (in Carrick parish, Co. Meath) from the local ruler of Fir Tulach, and thereafter the site was held by successive queens of Mide.
For almost a decade after the death in 1022 of his grandfather, the dynasty was wracked by internal strife. His immediate predecessors in the kingship of Mide were distant cousins; Máel-Sechnaill Got (the stammerer; d. 1025); Róen son of Muirchertach (slain 1027); and Domnall, perhaps a brother of Máel-Sechnaill Got. In 1030 Conchobar defeated Domnall Got in battle; although there is no evidence directly linking him to the latter's subsequent assassination (the killer is named as one Máel-Callainn), complicity might well be suspected. Conchobar gained the kingship at the expense of ‘na Goit’, and apparently maintained a vendetta with this collateral line. Whether or not he ordered the death of Cernachán Got (1037), he is expressly blamed for killing Flann son of Máel-Sechnaill Got in treacherous circumstances in 1042 and for slaying the son of Cernachán Got and Domnall ‘son of In Got’ (son of the earlier Domnall?) in 1056.
Conchobar was equally ruthless in suppressing opposition within his own family line. He blinded his uncles Muirchertach (1032) and Murchad (1039), presumably to prevent them from mounting a political challenge; ten years later, both were put to death, an action that the annalist insists was ‘contrary to a pledge given to God and man’. He blinded his own brother Flann (1037), but was apparently unable to contain Flann's son, Murchad. The latter had earlier defeated him (1033) in an encounter that cost the lives of several of his allies, including the king of Cenél Lóegaire. It seems that Conchobar eventually reached a modus vivendi with his nephew, and that Murchad attained the abbacies of Clonard and Kells – probably in 1055, when Abbot Ua Follamain of Clonard died. That same year, Murchad was in conflict with Dub-dá-Leithe (qv) of Armagh.
Efforts on the part of Conchobar to control the Hiberno-Norsemen of Dublin brought him into conflict with the Leinstermen. In 1035 the Hiberno-Norse king of Dublin, Sitriuc Silkbeard (qv) son of Amlaíb (Óláfr) Cuarán (qv) plundered the ecclesiastical centre of Ardbreccan, Co. Meath: Conchobar retaliated by sacking Swords in Co. Dublin. In an attempt to enforce his authority more firmly on the region, he repressed the local rulers of eastern Mide over the following three years, slaying three of the Caílle Follomain dynasty, and capturing the petty king of Gailenga. The latter's supporters attacked Clonard by way of reprisal, prompting Conchobar to ravage their territory. In 1040 he led an incursion into northern Leinster and sacked the ecclesiastical site of Láthrach Briúin (Laraghbryan, Co. Kildare).
Warfare with Leinster gathered pace in the course of the decade. In 1048 Conchobar laid waste the Liffey plain and plundered the sanctuary lands of Kildare. The local ruler of Uí Fháeláin responded with an attack on Clonard, but events took a more serious turn when the powerful overking of Leinster, Diarmait (qv) son of Donnchad Máel na mBó (qv), in alliance with the overking of Ulaid, Niall (qv) son of Eochaid, invaded Mide and burned many churches. Conchobar captured the king of Brega, Gairbith Ua Cathasaigh, whom he compelled to yield hostages. He executed these when Diarmait and Niall again invaded Mide in 1049 and, in a further reassertion of his rule, sacked the ecclesiastical site of Lann Léire. Conchobar secured support from the overking of Munster, Donnchad (qv) son of Brian Bórama (qv), who was engaged in a protracted conflict with Leinster. In 1053 he joined Donnchad in attacking the kingdom of Dublin, which Diarmait had appropriated for himself; they pillaged Fine Gall and sacked Lusk, but Diarmait struck back and devastated Mide from Slane westwards. Perhaps this action destabilised the authority of Conchobar to some degree; indeed the earlier conflict with Dublin in 1035 and the joint Leinster–Ulaid invasions of 1048–9 could be interpreted in a similar light. Each of these setbacks was followed by a wave of repression against his own dynasty and his sub-kings. After the 1053 incursions by the Leinstermen, he apparently made some agreement with his rebellious nephew Murchad. Then, in 1056, he slew two of ‘na Goit’ (as noted above); two years later, his oppression of Brega was so severe that Diarmait son of Donnchad Máel na mBó again intervened, but with limited success.
Repression and war characterised Conchobar's reign to the end. In 1065 he slew the local king of Gailenga, Leóchán grandson of Máelán. His kingdom was again ravaged by an invasion from Leinster in 1069, this time led by the king of Dublin, Murchad (qv) son of Diarmait son of Donnchad Máel na mBó. His enemies sacked Granard, Ardbreccan, and Fore, the king of Dublin being severely wounded in this last attack. The ultimate revenge came to Conchobar in 1072, when he defeated and slew his arch-enemy Diarmait son of Máel na mBó in the battle of Odba (Moathill, near Navan, Co. Meath). The following year, Conchobar was slain by his nephew, Murchad son of Flann, in violation of an oath taken on the Bachall Ísu – an important Patrician relic. He was buried in Clonmacnoise. On the Friday of Easter week following his death, his head was stolen from the sepulchre and brought to Cenn Corad (Kincora) on the instructions of the Munster overking Tairdelbach Ua Briain (qv) (d. 1086), who was a protégé of Diarmait son of Máel na mBó. The recovery of the head on the following Sunday and its return to its rightful resting place was regarded as a miracle wrought by St Ciarán (qv) of Clonmacnoise. Meanwhile, Murchad son of Flann took the kingship. He was slain by the Gailenga in 1076. The kingship passed to Conchobar's son Máel-Sechnaill Bán, but most of the later kings of Mide descended from the line of Flann.