Cellach mac Rogallaig
Cellach mac Rogallaig (or Cellach Locha Cime) (died 705) was a King of Connacht from the Uí Briúin branch of the Connachta. He was the son of Rogallach mac Uatach (died 649), a previous king. He succeeded his nephew Muiredach Muillethan mac Fergusso (died 702) as king in 702.
He reigned from 702 to 705. The king lists in this period vary in their order of kings. The reign of Cellach is misplaced in the king-lists who place his reign between Dúnchad Muirisci mac Tipraite (died 683) and Fergal Aidne mac Artgaile (died 696). Both the Annals of Tigernach and the Annals of Ulster call him King of Connachta at his death obit however in 705. To confuse matters further he is listed as the guarantor of the Cáin Adomnáin in 697 at the Synod of Birr as King of Connacht.
In July, 703 the high-king Loingsech mac Óengusso of the Cenél Conaill led a large army into Connacht to levy tribute but was defeated and slain along with many of his sons and other kings of the Ui Neill at the Battle of Corann (in South County Sligo). The saga tradition of this battle is preserved in the Fragmentary Annals of Ireland. According to this the bards of the high-king mocked Cellach for being an old shaky king. However Cellach:
sprang from his chariot swiftly and far from the chariot, and the cracking of the old man's bones was audible as he leaped out of the chariot. And after that he said, in a loud voice, springing to the nearby battle: ‘Connachtmen, defend and protect your own freedom, for the people who are against you are not nobler or braver than you, and they have not done any better than you up to now.’ And he was talking to them like that, with his voice quavering and his eyes on fire."
The Connaughtmen rose to the challenge and won the battle.
The reason for Loingsech's attack may have been because the Cenél nEógain had outflanked the Cenél Conaill in the north resulting in expansion into Connacht as the only option available for them as well as a desire by Loingsech to assert his authority as high king. It also may have been due to the pressure of the Uí Briúin on the Cenél Coirpri in the direction of Breifne which would have cut off the Cenél Conaill from their access to the midlands.
At his death obit in 705 in the annals it is mentioned that he entered the clerical life. He is also referred to as Cellach Locha Cime. This lake is now Lough Hackett, near Headford in modern County Galway. His children were called the Síl Cellaig and contested the kingship of Connacht with the Síl Muiredaig and Síl Cathail throughout the 8th century. They were later displaced from this area by the Uí Briúin Seóla.
- Byrne, Table 20;Mac Niocaill, pg.157
- Laud Synchronisms give him a 4 year reign and Book of Leinster gives him a 7 year reign
- Charles-Edwards, pg.584
- Annals of Ulster, AU 703.2; Annals of Tigernach, AT 703.2
- Fragmentary Annals of Ireland, FA 158
- Byrne, pg.247
- Mac Niocaill, pg.118
- AU 705.3; AT 705.7
- Byrne, pg.248
- Annals of Ulster at  at University College Cork
- Annals of Tigernach at  at University College Cork
- Byrne, Francis John (2001), Irish Kings and High-Kings, Dublin: Four Courts Press, ISBN 978-1-85182-196-9
- Charles-Edwards, T. M. (2000), Early Christian Ireland, Cambridge: Cambridge University Press, ISBN 0-521-36395-0
- Gearoid Mac Niocaill (1972), Ireland before the Vikings, Dublin: Gill and Macmillan
- Fragmentary Annals of Ireland at CELT: Corpus of Electronic Texts at University College Cork