Forggus mac Muirchertaig (died c . 566), also called Forrgus mac Maic Ercae, is included in most lists of High Kings of Ireland.
His father was Muirchertach mac Muiredaig, also called Mac Ercae, and his brother was Domnall Ilchelgach with whom he is said to have ruled jointly. He succeeded Diarmait mac Cerbaill, and was followed by Ainmuire mac Sétnai.
His death is recorded in Adomnán's Life of Saint Columba.
The less reliable evidence of the Irish annals records that he and Domnall defeated Eógan Bél, grandson of Ailill Molt, and then, c. 550, Éogan's son Ailill Inbanda further west, in the region of Clew Bay, modern County Mayo. He also fought Diarmait in alliance with Aimmuire.
Áedán mac Gabráin, also written as Aedan, was a king of Dál Riata from c. 574 until c. 609 AD. The kingdom of Dál Riata was situated in modern Argyll and Bute, Scotland, and parts of County Antrim, Ireland. Genealogies record that Áedán was a son of Gabrán mac Domangairt.
Diarmait mac Cerbaill was King of Tara or High King of Ireland. According to traditions, he was the last High King to follow the pagan rituals of inauguration, the ban-feis or marriage to goddess of the land. The last High King to observe the ancient pagan Feis Temrach or Assembly of Tara which took place on Samhain every three years to pass or renew laws, approve annals and records.
The Kings of Ailech were the over-kings of the medieval Irish province of Ailech in north-western Ireland. It encompassed the territories of the Cenél nEógain and Cenél Conaill. After the battle of Cloítech in 789 its kings were exclusively from the Cenél nEógain. The royal fort for Ailech was the Grianan of Aileach, a hillfort on top of Greenan Mountain in modern-day County Donegal, Republic of Ireland.
Ailill mac Nath Í, called Ailill Molt, is included in most lists of the High Kings of Ireland and is also called King of Connacht. His cognomen, molt, means "ram" but its origin is unknown.
Domhnall Mac Murchada, called Domnall Midi, was High King of Ireland. He belonged to the Clann Cholmáin branch of the Uí Néill. Clann Cholmáin's pre-eminence among the southern Uí Néill, which would last until the rise of Brian Bóruma and the end of the Uí Néill dominance in Ireland, dates from his lifetime.
Áed mac Ainmuirech was High King of the Northern Uí Néill. He belonged to the Cenél Conaill and was a distant cousin of Columba of Iona. He was the son of Ainmuire mac Sétnai, a previous possible high king. His mother was Bríg, daughter of Chobtaig, son of Ailill, son of Nath Í, son of Crimthann mac Énnai son of Énnae Cennsalach of the Uí Ceinnselaig dynasty from Leinster. He was born in 530 according to the Annals of Tigernach (596.2).
Domnall mac Áedo, also known as Domnall II, was an Irish king and son of Áed mac Ainmuirech and his consort Land, the daughter of Áed Guaire mac Amalgada of Airgíalla. Domnall was High King of Ireland from 628 until his death. He belonged to the Cenél Conaill kindred of the Northern Uí Néill.
Congal Cáech was a king of the Cruthin of Dál nAraidi in the medieval Irish province of Ulaid, from around 626 to 637. He was king of Ulaid from 627–637 and, according to some sources, High King of Ireland.
Áed mac Diarmato, called Áed Sláine, was the son of Diarmait mac Cerbaill. Legendary stories exist of Áed's birth. Saint Columba is said to have prophesied his death. His descendants, the Síl nÁedo Sláine—the seed of Áed of Slane—were prominent in 7th and early 8th century Ireland.
Muirchertach mac Muiredaig, called Mac Ercae, Muirchertach Macc Ercae and Muirchertach mac Ercae, was said to be High King of Ireland in the 6th century. The Irish annals contain little reliable information on his life, and the surviving record shows signs of retrospective modification. The Aided Muirchertaig Meic Erca takes as its theme Muirchertach's supernatural death.
Ainmuire mac Sétnai or Ainmire or Ainmere was a High King of Ireland from the Cenél Conaill branch of the Uí Néill. He was the great-grandson of Conall Gulban, founder of this branch. He ruled from 566 to 569. He was the first high king from the Cenél Conaill.
Loingsech mac Óengusso was an Irish king who was High King of Ireland. Loingsech was a member of the northern Cenél Conaill branch of the Uí Néill. Although his father Óengus had not been High King, his grandfather Domnall mac Áedo had been.
Eógan Bél mac Cellaig was a king of Connacht from the Uí Fiachrach branch of the Connachta. He was the grandson of the high king Ailill Molt. His reign began sometime after 500. His byname bél means "mouth" or "lip," supposedly because he received praise from all who encountered him as a child. Other sources claim he had a cleft lip.
Dauí Tenga Uma was a King of Connacht from the Uí Briúin branch of the Connachta.
Diarmait was a son of Áed Sláine. According to the Irish annals, he was High King of Ireland.
Blathmac was a son of Áed Sláine. According to the Irish annals, he was High King of Ireland.
Murchad mac Diarmato, called Murchad Midi, was an Irish king. One of four or more sons of Diarmait Dian, he succeeded his father as King of Uisnech at the latter's death in 689.
Domnall mac Muirchertaig, called Domnall Ilchelgach and Domnall mac Maic Ercae, was said to be a High King of Ireland.
Duinseach ingen Duach, Queen of Tara, fl. 500.