Brega was annexed in the 6th century by the Uí Néill. By the middle of the 8th century the Síl nÁedo Sláine had split into two hostile branches: Southern Brega, or the Kingdom of Loch Gabhair, which was ruled by the Uí Chernaig; and Northern Brega, or the Kingdom of Cnogba/Knowth, which was ruled by the Uí Chonaing. Despite this, many kings of Brega ruled over both areas, and thus Brega as a whole, until the kingdom's extinction in the early years of the Norman invasion of Ireland.
Kings of Brega
Persons in bold considered to be High Kings of Ireland.
List incomplete: see Mac Shamhráin, 2004. The Uí Chonaing had earlier been settled around Tailtiu and Ráith Airthir in the valley of the Blackwater; that district was left to another branch of Síl nÁeda Sláne, Síl nDlúthaig upon the conquest of the Ciannachta Breg during the reign of Cináed mac Írgalaig. The title King of Ciannachta is first used by this dynasty in the Annals of Ulster in the year 742 and the use of the title King of Cnogba in 818; prior to this, it was a title used by the Ciannachta themselves. Earlier kings can be considered chiefs of the Uí Chonaing.
List incomplete: see Mac Shamhráin, 2004. The title King of Southern Brega does not appear in the Annals of Tigernach until 729 and in the Annals of Ulster until 751. Earlier rulers can be considered rulers of the Uí Chernaig sept of Síl nÁedo Sláine.
Diarmait mac Etersceili (died 868) (rí Locha Gabor)
Máel Sechnaill mac Néill (died 870) (leth-rí Desceirt Breagh)
Tolarg mac Cellaig (died 888) (leth-rí Desceirt Breagh)
Máel Ograi mac Congalaig (died 908) (rí Locha Gabor)
Fogartach mac Tolairg (died 916) (rí Desceirt Breagh)
Beollán mac Ciarmaic (died 969) (rí Locha Gabor)
Gilla Mo Chonna mac Fogartach mac Ciarmac (rí Deiscert Breg), died 1013
^T. M. Charles-Edwards, Early Christian Ireland (2000), p. 15; James Henthorn Todd, Cogad Gaedel re Gallaib (1867), p. L.
^This list is based on Francis J.Byrne, Irish Kings and High Kings, Appendix II; T.M.Charles Edwards, Early Christian Ireland, Appendix II; with gaps filled in by the poem Síl Aeda Sláne Na Sleg found in the Book of Leinster
S. Ma na Midhe, Some notes on Navan, ancient and modern, Riocht na Midhe 1/1, 1955, pp. 53–60
Byrne, Francis John, Historical note on Cnogba (Knowth), in Excavations at Knowth, Co. Meath, 1962–65 (George Eogan ed.), Proc. RIA C 66, pp. 383–400; Irish Kings and High-Kings, Batsford, London, 1973. ISBN 0-7134-5882-8; A nnote on Trim and Sletty, Peritia 3, pp. 316–19
D. O Murchadha, Odhbha and Navan, Riocht na Midhe 8/4, 1992–93, pp. 112–23
Mark Clinton, Settlement Dynamics in Co. Meath:the Kingdom of Loegaire, Peritia 14, pp. 372–401, 2000
Ailbhe Mac Shamhráin, Church and dynasty in Early Christian Brega: Lusk, Inis Pátraic and the cast of Máel-Finnia, king and saint, Table 8.1, Lineages of Síl nÁedo Sláine, p. 127; in The Island of St Patrick: Church and ruling dynasties in Fingal and Meath, 400–1148, (ed.) Mac Shamhráin, Four Courts, 2004.