pointers on Irish archival records and early genealogies

Viestit: 31
Sukupuu: Graafinen
Tarkastele heidän sukupuutaan.
Good day,

I'm trying to do some research on a family or clan name "Mag Fhionnbhairr", I guess specifically if the name Gannes originates from it.
Can anyone guide me on research resources for early medieval (pre-1300) records that might be useful?

Sincere regards,

Palaa sivulle “Ireland”