Ui Briuin and Uí Fiachrach
Eochaidh Mugmedon was king of Connacht at the end of the fourth century. In early historical times his offspring: separated into three dynasties --
  • Brioin the Uí Briuin, ancestors to the Síl Murray (O Conors and MacDermots) and In the seventh century the Uí Briuin began separating into three branches --
    • Ui Briuin Seola (O Flahertys)
    • Ui Briuin Breffney (O Rourkes and O Reillys)
    • Ui Briuin Ai (O Conors, MacDermots and others)
  •  
  • Fiachra the Uí Fiachra, ancestors to the O Dowds and O Heynes
 

Regional references from the Annals (Regional Kings, i.e. rí or rex) 

Fiachrach
U603.2 Mael Cothaid, rex Nepotum Fiachrach, in fugam euersus est. 
U735.4 Airectach nepos Duncadho Mursce, rex Nepotum Fiachrach
U750.9 Mors Con Dinaisc nepotis Forgguso di Auibh Fiachrach
U784.7 Bellum Cairn Conaill i n-Aidniu ubi Tipraiti uictor & Nepotes Fiachrach uicti. 
U787.6 Ar Nepotum Briuin h-Umil apud Nepothes Fiachrach Muirsce ubi omnes optimi circa regem Flathgalum filium Flannabrat, ceciderunt. 
U792.4 Mael Bresail m. Aedho filii Crichain ri H. Fiachrach
U816.8 Bellum do madhmaim for h-U Fiachrach Muirsce re n-Diarmait m. Totaigh, 
U816.9 Mors Cathail m. Ailello regis Nepotum Fiachrach