Forggus mac Muirchertaig (died c

Circa

Circa , usually abbreviated c. or ca. , means "approximately" in the English language, usually referring to a date...

. 566), also called Forrgus mac Maic Ercae, is included in most lists of High Kings of Ireland.

Father Muirchertach mac Muiredaig

Muirchertach mac Muiredaig

Muirchertach mac Muiredaig , called Mac Ercae, Muirchertach Macc Ercae and Muirchertach mac Ercae, was said to be High King of Ireland. The Irish annals contain little reliable information on his life, and the surviving record shows signs of retrospective modification...

, also called Mac Ercae, brother Domnall Ilchelgach

Domnall Ilchelgach

Domnall mac Muirchertaig , called Domnall Ilchelgach and Domnall mac Maic Ercae, was said to be a High King of Ireland....

 with whom he is said to have ruled jointly. Succeeded Diarmait mac Cerbaill

Diarmait mac Cerbaill

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....

, followed by Ainmuire mac Sétnai

Ainmuire mac Sétnai

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 566-569...

.

Death recorded in Adomnán's Life

Hagiography

Hagiography is the study of saints.From the Greek and , it refers literally to writings on the subject of such holy people, and specifically to the biographies of saints and ecclesiastical leaders. The term hagiology, the study of hagiography, is also current in English, though less common...

of Saint Columba

Columba

Saint Columba —also known as Colum Cille , Colm Cille , Calum Cille and Kolban or Kolbjørn —was a Gaelic Irish missionary monk who propagated Christianity among the Picts during the Early Medieval Period...

.

The less reliable evidence of the Irish annals

Irish annals

A number of Irish annals were compiled up to and shortly after the end of Gaelic Ireland in the 17th century.Annals were originally a means by which monks determined the yearly chronology of feast days...

 records that he and Domnall defeated Eógan Bél

Eógan Bél

Eógan Bél mac Cellaig was a king of Connacht from the Ui Fiachrach branch of the Connachta. He was the grandson of the high king Ailill Molt. His reign began sometime after 500....

, grandson of Ailill Molt

Ailill Molt

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....

, and then, circa 550, Éogan's son Ailill Inbanda

Ailill Inbanda

Ailill Inbanda mac Eógain was a king of Connacht from the Ui Fiachrach branch of the Connachta. He was the son and successor of Eógan Bél, who was slain by the northern Ui Neill in 542. His nickname Inbanda means "womanish" or effeminate or it could mean "the vigorous" which is more likely .His...

 further west, in the region of Clew Bay

Clew Bay

Clew Bay is a natural ocean bay in County Mayo, Ireland. It contains Ireland's best example of sunken drumlins. According to tradition, there is an island in the bay for every day of the year. The bay is overlooked by Croagh Patrick, Ireland's holy mountain, and the mountains of North Mayo. Clare...

, modern County Mayo

County Mayo

County Mayo is a county in Ireland. It is located in the West Region and is also part of the province of Connacht. It is named after the village of Mayo, which is now generally known as Mayo Abbey. Mayo County Council is the local authority for the county. The population of the county is 130,552...

. Also fought Diarmait in alliance with Aimmuire.