Domnall Ardmacha" of Armagh" ( K. Ireland 956 to 980 ).
Was the first of the line to be styled " O'Neill" ( Ua Néill or grandson of Niall ), being possibly the first Irishman of station to assume what became an hereditary surname; it may have been intended as a quasi-title during the period 944-56, when to be a grandson of Niall "Black-Knee" implied rightful inheritance of the High Kingship ( despite the usurpation of Congalach ( K. ofBrega ), who had seized the High Kingship by force of arms.
Domnall was a patron of learning, and gave " the full of St Patrick's Bell of Silver" to the Archbishop of Armagh in 947.
In 962 he carried light boats overland and raided the Danes in the lake dwelings and islands on Lough Ennell; he raided the settlers again in 969, burning 300 of them in one house.
He defeated and overran Meath in 970, and killed Gillacoluim ( K. of Tír Conall ) in 977. He died 980 at Armagh, after serving a long penance for his sins. He married Mor, who was probably a daughter of Tadhg" of the three Towers" ( K. of Connaugh ), and had issue:
(1) Muircheartach Midheach ( Royal Heir of Ireland ),
(2) Muiredach, who had two sons
(1) Muircheartach, killed 1015 by Conchobhar O' Domhnallian
(2) Lochlann whose dynasty took the surname Mac Lochlainn. His son Ardgar ( K. of Ailech 1061 to 1064 ) held the local kingship of Tulach Óg in 1051, when he was expelled bt Aedh O'Neill, another grandson of Nial l" Black Knee". He was restored to Tulach Óg in 1054 and promoted to Ailech in 1061.
He died 1064 at Tulach Óg and was buried in the royal tomb at Armagh.
His eldest son, Domnall ( K. of Ireland 1119 to 1121 ) was perhaps the most warlike and most capable ruler of his time, was the ancestor of the Mac Lochlainn kings of the Cinel Eoghain, of whom the last, King Domnall, was killed in 1241 by Brian O'Neill his successor.
Ten of King Domnall's immediate family died on the battlefield, as well as all the other Cinel Eoghain chieftains who opposed Brian O'Neill.
Aedh Craoibh Tulcha ( K. of Ailech 989 to 1004 ), defeated the Ulidians 1004 at Craebh Tulcha, where the Ulidian kings were inaugurated under the sacred tree ( the Craebh ) at Crewe, Antrim; however, he was killed in his moment of victory at the age of 28 and left issue.
Aedh II ( da Aedh ) Royal heir in the North, who was called by the same name as his older brother, and was killed 1021.
Muircheartach Midheach of Meath probably got his nickname from being fostered in Meath, it being traditional that the sons of kings and chiefs be fostered among the Gaels. He was killed in battle 977 against his uncle, Olaf ( K. of Dublin ), leaving a son:
Flaithbertach an Trostain" of the pilgrims staff, ( K. of Ailech 1004 to 1030 and 1033 to 1036 ) was constanly at war with King Brian Borama ( or Boru ), the usurping king of Ireland and ancestor of the O'Briens, who took hostages from him in 1010 and carried off a larg cattle raid on Tír Conaill in 1012.
Flaithbertach supported the restoration of Maelsechlainn" the Great" as High King in 1014 ( the last of the southern Ui Néill to be King of Ireland ). Also during his reign, the capital was moved from Ailech itself to Tulach Óg ( Tullyhogue ), where the later O'Neills were inaugurated on a sacred stone in a grove by the O'Cane, their most powerful under-king and hereditary inaugurator, and the O'Hagan, lawgiver to O'Neill"
Flaithbertach resigned his throne in 1030 and went on pilgrimage to Rome, resuming his power after his sons death in 1033.
He died in 1036, He died leaving issue:
Aedh Athlamhan The Handy ( K. of Ailech )
Domnall, Died 1027.
Muircheartach, local king of Tulach Óg, punished the men of Mughdorna in 1044 for violation of an oath sworn on St Patricks Bell, which han been given to the Cinel Eoghain by St Cainech. He was pursued and killed 1046 at the mouth of the Ardee while returning fron a raid into Brega.
Muiredach, killed 1039 by the O'Lavertys
Muiredach ( Royal heir of Ailech ) named like his older brother, was burned to death 1046 in a house fire by Cu-Uladh, local king of Uachtar thire.
Aedh Athlamhan " the handy " ( K. of Ailech 1030 to 1033, Royal heir of Ireland ), was given the throne during his father's pilgrimage to Rome but died November 1033, he had issue:
Domnall an Togdhamh " the young Ox "
Anrothan, who is said to have married a daughter of the K. of Scots ( probably the local K. of Argyle ) and to have received wide lands after campaigning there.
Domnall an Togdhamh " the young Ox " styled king of Ulster "with opposition," was O'Neill pretender to the northern throne for five years, he was killed by Mac Lochlainn, the effective king, though the O'Neills still held the local kingdon of Tulach Óg. His Son:
Flaithbertach Locha Feadhaidh, also styled king of Ulster "with opposition," was O'Neill pretender to the northern throne for three years when he came of age, but was defeated in the long struggle for supremacy within the Cinel Eoghain and was killed by Mac Lochlainn, the effective king. He had a son:
Conchobar na Fiodhbhuidhi " of the woods " also styled king of Ulster " with opposition," was O'Neill pretender to the northern throne for 10 years when he came of age, but was killed by his rival Mac Lochlainn, the effective king. His son:
Tadhg Glinne " of the Glens," also styled king of ulster " with opposition, was O'Neill pretender to the northern throne for seven years before he was killed by the Mac Lochlainn chief, the effective. His Son:
Muircheartach Muighe Line " of Moylinny," also styled king of Ulster " with opposition," was O'Neill pretender to the northern throne for five years, and was, like his predecessors, local king of Tulach Óg. He was " undeservedly slain" with four of his sons 1160 after winning the Battle of Magh-Luadhat against Lochlainn Mac Lochlainn. He left one surviving son, Aedh Macaemh Toinleasg.