Niall Noígíallach (Old Irish "having nine hostages"), or in English, Niall of the Nine Hostages, son of Eochaid Mugmedón, was an Irish king, the ancestor of the Uí Néill family that dominated Ireland from the 6th to 10th centuries. The rise of the Uí Néill dynasties and their conquests in Ulster and Leinster are not reliably recorded and have been the subject of considerable study and attempts to reconstruct them.
The small passage tomb known as the Mound of the hostages or Duma na NGiall dates to around 2500BC. The tomb gets its name from the custom of Irish kings taking important people hostage, one of these kings was known as Niall of the Nine Hostages who had taken hostages from all of the provinces of Ireland and from other countries. The passage tomb is one of only two monuments at Tara that have been excavated.
The famous 9th century Celtic cross of King Flann, High King of Ireland, depicts St. Columba between two angels, the Last Judgement, Christ with Peter and Paul and the founding of the monastery with St. Ciaran and King Dermot.
Brian Boru was probably the most successful warlord king in Irish history. He is known as the last High King of Ireland and is even credited with seeing off the Vikings who had terrorised the Irish for over 200 years.
Cormac mac Airt (son of Art), was, according to medieval Irish legend and historical tradition, a High King of Ireland. He is probably the most famous of the ancient High Kings, and may have been an authentic historical figure, and his reign is variously dated as early as the 2nd century and as late as the 4th. He is said to have ruled from Tara, the seat of the High Kings of Ireland, for forty years, and under his rule Tara flourished. He was famous for his wise, true, and generous…
Lóegaire mac Néill - Lóegaire (floruit fifth century) (died c. 462), also Lóeguire, is said to have been a son of Niall of the Nine Hostages. The Irish annals and king lists include him as a King of Tara or High King of Ireland. He appears as an adversary of Saint Patrick in several hagiographies. His dealings with the saint were believed to account for his descendants' lack of importance in later times.