Pedigree of the Ua Brolchains (Left to Right) -
Neill 'of the Nine Hostages' Eoghain (Cenel Eoghainn) Muiredaigh
Feradaigh (Cenel Feradaigh)
Fiachna Suibhne mend King of Ireland
d. 623
Chief of Cenel Eoghainn 650

Maili Tuile
Flann find
Chief of Cenel Eoghainn
d. 698
Diochon Elgine Brolchain (O Brolchainn)
Doiligein 1053
Royal priest of Armagh
Mael patraicc Duibh insi Maoil Brigdhe Mac an t-Saoir Ua Brolchain Bishop of Kildare
d. 1097

Diermada | Aedha | Muiregein | Maoil Iosa an cleiricc O Brolchain d. 1086
There is a Ballybrollaghan in Donegal, Banagh Barony, Parish of Inver. Bally means "homeland," so this is a reference to the "homeland of the O Brolchains." All of the MacAteers except one in the 1665 Hearth Money Rolls were to be found in Banagh Barony (Barrony of Boylagh & Banagh), where they also appear in the Census of 1659. The surname O Brolchain is anglicised in various ways, O Brollaghan, O Brillaghan, etc. This can only be a reference to the O Brolchains of Donegal, of whom Mael Brighte mac an t-saoir Ua Brolchain was an ancestor.
MacLysaght (Irish Families map) places their homeland further north, just south of Derry and the Inishowen Peninsula; so this may have been their original homeland (Ballybrollaghan).
Census of 1659 - Donegal Inishowen Barony
Principal Irish Names
O Barr (7), O Brillaghan (23), O Boyle (8), O Cally (22), McCallin (15), O Callane & O Cullane (12,27), O Conagill (9), O Carran (16), O Currin (3, 19), O Carny (10), McCollgan (30), McConway (6), O Callaghan (8), O Doghertye (203), O Doy (6), O Deuer (8), McDevet (27), O Donell (20), O Dermond (35), O Deveny (9), O Farran (14), McGlaghlin (76), O Granny (6), McGillneske (8), O Gollogher (12), O Herrall (8), O Hegerty (23), O Harkan (21), O Knawsie (9), O Kelly (11), McKay (6), O Lunshaghan (22), McLaughlin (63), O Luog (9), O Mrisane (7), O Moran (6), O Mulloy (7), McMurray (8), O Muncy (8), Porter (11), O Quigley (25), O Rodan (13), O Sheale (8), O Towlan (14), McVagh (6).