Forggus mac Cellaig (or Fergus mac Cellaig) (died 756) was a King of Connacht from the

Uí Briúin The Uí Briúin were a royal dynasty of Connacht. Their eponymous apical ancestor was Brión, son of Eochaid Mugmedon and Mongfind, and an elder half brother of Niall of the Nine Hostages. They formed part of the Connachta, along with the ...

branch of the

Connachta The Connachta are a group of medieval Irish dynasties who claimed descent from the legendary High King Conn Cétchathach (Conn of the Hundred Battles). The modern western province of Connacht ( Irish ''Cúige Chonnacht'', province, literall ...

. He was the son of

Cellach mac Rogallaig Cellach mac Rogallaig (or Cellach Locha Cime) (died 705) was a King of Connacht from the Uí Briúin Sil Cellaig branch of the Connachta. He was the son of Rogallach mac Uatach (died 649), a previous king. He succeeded his nephew Muiredach Mui ...

(died 705), a previous king and brother of

Domnall mac Cellaig Domnall mac Cellaig (died 728) was a King of Connacht from the Uí Briúin branch of the Connachta. He was the son of Cellach mac Rogallaig (died 705), a previous king.Francis J.Byrne, ''Irish Kings and High-Kings'', Table 20 The sept of Ui Briun ...

(died 728). The sept of Uí Briúin he belonged to was the Síl Cellaig of Loch Cime (Lough Hackett, near Headford in modern County Galway) named for his father. He reigned from 742 to 756. Events occurred in his reign which helped to weaken the other branches of the Connachta. In 743 a battle was fought between the

Uí Fiachrach Aidhne Uí Fhiachrach Aidhne (also known as Hy Fiachrach) was a kingdom located in what is now the south of County Galway. Legendary origins and geography Originally known as Aidhne, it was said to have been settled by the mythical Fir Bolg. Dubhalta ...

and their ex-allies the Uí Maine. Also in 743 the Ui Aillelo fought a battle in Mag Luirg (Moylurg, the plains of Boyle) with the Gailenga. Fergus himself had to impose his authority and in 746 in alliance with the Conmaicne he was defeated by opponents from the Uí Briúin. That same year he slaughtered The Uí Briúin Seóla branch in southern Connacht. In 752 the Ui Briun destroyed the Calraige Luirg, who were possibly vassals of the Ui Aillelo. In 753 the Ui Aillelo were slaughtered by the Grecraige. The Ui Briun expansion to the north met with the hostility of the

Cenél Coirpri Tethbae (; also spelled ''Tethba'', often anglicised ''Teffia'') was a confederation of túatha in central Ireland in the Middle Ages. It was divided into two distinct kingdoms, north Tethba, ruled by the Cenél Coirpri, and south Tethba, ruled ...

branch of the

Uí Néill The Uí Néill (Irish pronunciation: ; meaning "descendants of Niall") are Irish dynasties who claim descent from Niall Noígíallach (Niall of the Nine Hostages), a historical King of Tara who died c. 405. They are generally divided into t ...

. In 754 was fought the Battle of Ard Noíscan (Ardneeskin) in Ui Aillelo territory between the Ui Briun and the Cenel Coipri. In 756 he inflicted a heavy defeat on them at the Battle of Móin Mór (in modern County Longford). Forggus ensured the support of Clonmacnoise by promulgating the Law of

Ciarán of Clonmacnoise Saint Ciarán of Clonmacnoise (c. 516 – c. 549), supposedly born Ciarán mac an tSaeir ("son of the carpenter"), was one of the Twelve Apostles of Ireland and the first abbot of Clonmacnoise. He is sometimes called Ciarán the Young ...

and the Law of

Brendan Brendan may refer to: People * Saint Brendan the Navigator (c. 484 – c. 577) was an Irish monastic saint. * Saint Brendan of Birr (died 573), Abbot of Birr in Co. Offaly, contemporaneous with the above * Brendan (given name), a masculine given na ...

of Clonfert in 744. His son

Colla mac Fergusso Colla mac Fergusso (or Colla mac Forgusso, died 796) was a possible King of Connacht from the Uí Briúin branch of the Connachta. He was the son of Forggus mac Cellaig (died 756), a previous king. The sept of Uí Briúin he belonged to was the S ...

(died 796) was also a king of Connacht. Three of his sons Catharnach, Cathmug, and Artbran were slain in 758 at the Battle of Druim Robaig (Dromrovay, southern modern County Mayo) by the

Uí Fiachrach The Uí Fiachrach () were a royal dynasty who originated in, and whose descendants later ruled, the ''coicead'' or ''fifth'' of Connacht (a western province of Ireland) at different times from the mid-first millennium onwards. They claimed descen ...

in 758.Byrne, pg.249;Mac Niocaill, pg.135; Ó Cróinín, pg.233; AU 758.4; AT 758.4 where they are called grandsons of Cellach; ''Annals of the Four Masters'' refers to them as sons of Fergus

Notes

References

* ''Annals of Ulster'' a

a
University College Cork
* ''Annals of Tigernach'' a

a
University College Cork
* Byrne, Francis John (2001), ''Irish Kings and High-Kings'', Dublin: Four Courts Press, * Mac Niocaill, Gearoid (1972), ''Ireland before the Vikings'', Dublin: Gill and Macmillan * Ó Cróinín, Dáibhí (2005), ''A New History of Ireland'', Volume One, Oxford: Oxford University Press *Ó Corráin, Donnchad (1972), ''Ireland Before the Normans'', Dublin: Gill and Macmillan

External links

a
University College Cork
{{DEFAULTSORT:Forggus Mac Cellaig 756 deaths Kings of Connacht People from County Galway 8th-century Irish monarchs Year of birth unknown