The genealogy from Lochlainn to Domhnall (died 1121) is based upon the genealogical text in Rawlinson B502 . Beyond this the genealogy has been constructed from the genealogical text in the Book of Leinster  and from entries in the annals. This piecemeal approach is neccessary because of problems with the Book of Leinster text (as discussed elsewhere) but also because there is no known genealogical text bridging the generations between Muircheartach (killed 1166) and Domhnall of Cameirge. This gap reflects the general hiatus in Irish genealogy resulting from the thirteenth century repudiation of native secular learning by the Church as it came under greater foreign influence. Only in the fourteenth century did the secular schools resume the compilation of genealogical material.
Lochlainn | Ardghal died 1064 | Domhnall died 1121 |_________________________ | | | Niall, Maghnus Conor killed 1119 killed 1128 killed 1136 | Muircheartach Aedh killed 1166 | |________________________________________ | | | | | | Conor Niall Maelsechnaill Muircheartach Domhnall killed 1170 killed 1176 killed 1185 killed 1196 killed 1188 |____________ | | Conor beg Domhnall of Cameirge killed 1201 killed 1241
The pre-hiatus MacLochlainn genealogy terminates with Muircheartach killed 1166 but when compilation resumed it seems that the MacLochlainn genealogy was not traced beyond Domhnall of Cameirge. This is presumably because the near annihilation of the family at Cameirge in 1241 reset him as the nodal ancestor and his ascent required no elaboration. The only way that this gap can now be bridged is by reconstructing the missing segment from entries in the annals. The annals typically record several attributes relating to the individuals that come to their notice (personal name, epithet, patronymic, surname, position/office, location, date). In reconstructing a genealogy the attribute that interests us the most is the patronymic, a mini-genealogy in the form X mac Y ('X son of Y'), X ua Y ('X grandson of Y') or occasionally a longer string such as X mac Y meic Z ('X son of Y son of Z'), though that patronymics transform into surnames when not literally true and that a genealogy is required to determine the literal truth of a patronymic is a circularity that should always be borne in mind when parsing these materials.
A patronymic can be used to reconstruct a genealogy only if the attributes of the individuals being linked can be harmonised within a reasonable chronological framework. Within these terms patronymics in the Annals of Ulster clearly identify Conor, Niall, Maelsechnaill and Muircheartach as sons of Muircheartach killed 1166 . Conor beg would seem from his epithet (beg, 'small') to have been killed while still in his youth and so the patronymic given in the Annals of the Four Masters can be seen to identify him as son of Muircheartach killed 1196 rather than Muircheartach killed 1166 . At this stage we can immediately discern a customary succession from brother to brother before passing on to the next generation, broken only in circumstances of extreme mortality within a brotherhood as evidenced by the absence of brother to brother succession after the downfall of Muircheartach killed 1166 and the intrusion of Domhnall son of Aedh in the next generation . It has not been possible to determine where Aedh fits into the wider genealogy but given the very recent origins of the dynasty it seems likely that Aedh was a brother who did not survive Muircheartach killed 1166 or was his first cousin. The principle of seniority  is clearly at work here with Domhnall acting as regent for the youngest brother after Maelsechnaill was killed in 1185.
Unfortunately the patronymic of Domhnall of Cameirge is not recorded in the annals and so his paternity cannot be attested in this way, though his attributes harmonise so completely (personal name Domhnall, surname MacLochlainn, position/office ruler of Tír nEoghain, location the north, date mid-thirteenth century) that we may adopt a fallback position and evaluate alternative ascents on the basis of chronology and custom alone. Within these terms we can posit that Domhnall of Cameirge was killed in 1241 aged 71 or older with father Conor, 65 or older with father Niall, 56 or older with father Maelsechnaill or 45 or older with father Muircheartach. The latter offers the best fit to both the customary succession and to the chronological profile disclosed in the Annals of Ulster (Domhnall of Cameirge among the anonymous sons of MacLochlainn fighting rivals in Derry 1213/1214=aged 17/18 and politically active by 1232=aged 36) and so on these grounds we can identify the father of Domhnall of Cameirge as Muircheartach killed 1196.