Cermna Finn, son of Ebric and a great, great grandson of Míl Espáine

Míl Espáine

In Irish origin legends, Míl Espáine or Míl Espáne is the ancestor of the final inhabitants of Ireland, the "sons of Míl" or Milesians, who represent the vast majority of the Irish Gaels....

, was, according to medieval Irish legend and historical tradition, joint High King of Ireland

High King of Ireland

The High Kings of Ireland were sometimes historical and sometimes legendary figures who had, or who are claimed to have had, lordship over the whole of Ireland. Medieval and early modern Irish literature portrays an almost unbroken sequence of High Kings, ruling from Tara over a hierarchy of...

 with his brother Sobairce.

The pair came to power after Cermna killed the previous incumbent, Eochaid Étgudach

Eochaid Étgudach

Eochaid or Eochu Étgudach or Etgedach son of Dáire Doimthech, a descendant of Lugaid mac Ítha, nephew of Míl Espáine, was, according to medieval Irish legend and historical tradition, a High King of Ireland...

, in battle at Tara

Hill of Tara

The Hill of Tara , located near the River Boyne, is an archaeological complex that runs between Navan and Dunshaughlin in County Meath, Leinster, Ireland...

. They were the first High Kings to come from the Ulaid

Ulaid

The Ulaid or Ulaidh were a people of early Ireland who gave their name to the modern province of Ulster...

. They divided the country between them, the border running from Drogheda

Drogheda

Drogheda is an industrial and port town in County Louth on the east coast of Ireland, 56 km north of Dublin. It is the last bridging point on the River Boyne before it enters the Irish Sea....

 to Limerick

Limerick

Limerick is the third largest city in the Republic of Ireland, and the principal city of County Limerick and Ireland's Mid-West Region. It is the fifth most populous city in all of Ireland. When taking the extra-municipal suburbs into account, Limerick is the third largest conurbation in the...

. Cermna ruled the southern half from Dún Cermna (which Keating

Geoffrey Keating

Seathrún Céitinn, known in English as Geoffrey Keating, was a 17th century Irish Roman Catholic priest, poet and historian. He was born in County Tipperary c. 1569, and died c. 1644...

 identifies as Downmacpatrick in Kinsale

Kinsale

Kinsale is a town in County Cork, Ireland. Located some 25 km south of Cork City on the coast near the Old Head of Kinsale, it sits at the mouth of the River Bandon and has a population of 2,257 which increases substantially during the summer months when the tourist season is at its peak and...

, County Cork

County Cork

County Cork is a county in Ireland. It is located in the South-West Region and is also part of the province of Munster. It is named after the city of Cork . Cork County Council is the local authority for the county...

), Sobairce the northern half from Dún Sobairce (Dunseverick

Dunseverick

Dunseverick is a hamlet and townland near the Giant's Causeway in County Antrim, Northern Ireland. It is most notable for Dunseverick Castle.-External links:****...

 in County Antrim

County Antrim

County Antrim is one of six counties that form Northern Ireland, situated in the north-east of the island of Ireland. Adjoined to the north-east shore of Lough Neagh, the county covers an area of 2,844 km², with a population of approximately 616,000...

).

They ruled for forty years. Cermna was killed by Eochaid Faebar Glas

Eochaid Faebar Glas

Eochaid Faebar Glas, son of Conmáel, was, according to medieval Irish legend and historical tradition, a High King of Ireland. His epithet means "blue-green sharp edge"...

, son of the previous High King Conmáel

Conmael

Conmáel, son of Éber Finn, according to medieval Irish legend and historical traditions, became High King of Ireland when he killed Ethriel, son of Íriel Fáid, in the Battle of Rairiu. He was the first Milesian High King to have been born in Ireland, and the first to have been based in Munster...

, in the battle of Dún Cermna. Sobairce died in the same year at the hands of Eochaid Menn, son of the king of the Fomorians

Fomorians

In Irish mythology, the Fomoire are a semi-divine race said to have inhabited Ireland in ancient times. They may have once been believed to be the beings who preceded the gods, similar to the Greek Titans. It has been suggested that they represent the gods of chaos and wild nature, as opposed to...

. The Lebor Gabála Érenn

Lebor Gabála Érenn

Lebor Gabála Érenn is the Middle Irish title of a loose collection of poems and prose narratives recounting the mythical origins and history of the Irish from the creation of the world down to the Middle Ages...

synchronises their reign with those of Laosthenes in Assyria

Assyria

Assyria was a Semitic Akkadian kingdom, extant as a nation state from the mid–23rd century BC to 608 BC centred on the Upper Tigris river, in northern Mesopotamia , that came to rule regional empires a number of times through history. It was named for its original capital, the ancient city of Assur...

 and Rehoboam

Rehoboam

Rehoboam was initially king of the United Monarchy of Israel but after the ten northern tribes of Israel rebelled in 932/931 BC to form the independent Kingdom of Israel he was king of the Kingdom of Judah, or southern kingdom. He was a son of Solomon and a grandson of David...

 in Judah

Kingdom of Judah

The Kingdom of Judah was a Jewish state established in the Southern Levant during the Iron Age. It is often referred to as the "Southern Kingdom" to distinguish it from the northern Kingdom of Israel....

. The chronology of Geoffrey Keating's Foras Feasa ar Éirinn dates their reign to 1155-1115 BC, that of the Annals of the Four Masters

Annals of the Four Masters

The Annals of the Kingdom of Ireland or the Annals of the Four Masters are a chronicle of medieval Irish history...

to 1533-1493 BC.