Lyons Hill was the inauguration site for members of one of three septs of the Uí Dúnlainge dynasty which rotated the kingship of Leinster between 750-1050, after which the family became Normanised as the FitzDermots.
In that period 10 Uí Dúnchada Kings of Leinster established their base at Lyons. Their influence helped secure a placemyth for Cnoch Liamhna among 300 locations featured in Dinnshenchas Érenn, the poem Liamuin.
The Toraíocht of Liamuin was based on the mythical pursuit of a beautiful daughter of King Dúbhthach Dubthaire.
The Lyons kings were:
- 760-776 Cellach. Cellach mac Dunchad,
- 795-808 Finsnechta. Finsnechta Cethardec mac Cellach,
- 834-8 Bran. Bran mac Finsnechta,
- 854-62 Ruarc. Ruarc mac Bran,
- 884-5 Muiredach. Muiredach mac Bran,
- 917-23 Fáelán. Faelan mac Muiredach,
- 942-3 Lorcán. Lorcan mac Faelan,
- 958-66 Cellach. Cellach mac Faelan,
- 978-84 Domnall Claen. Domnall Claen mac Lorcan,
- 984-1003 Donnchad. Donnchad mac Domnall Claen.
The arrangement of the three septs of the Uí Dúnlainge to exchange the kingship of Leinster in rotation was almost unique in Irish history. It meant that by the end of the three century-arrangement, monarchs who were seventh cousins were swapping the kingship. By then the dynasty, traditionally clients of the Uí Néill, had become weakened by the battle for control of the region between Brian Bóruma of Dál Cais, the Uí Néill king Máel Sechnaill mac Domnaill and the Viking kingdom of Dublin, as well as the Uí Chennselaig of South Leinster.
The Uí Dúnchada dynasty held an important ecclesiastical role within the triumvirate, the Abbacy of Kildare, and Muiredach was simultaneously abbot and Kings of Leinster.
The Uí Néill clientship dates to 806 when High King Aed Oirdnide mac Néill invaded Leinster and deposed Finsnechtae. Finsnechtae regained the kingdom, presumably with Uí Néill support until his death in 808 causing dynastic strife and a further invasion of the High King. When Bran was “ordained” King of Leinster in 835 by High king Niall Caille mac Áedo it may have been the first instance of ordination of a king in European history. Muirchertach mac Néill, King of Aileach, paid an official visit to Cnoch Liamhna in 941.
After Cellach’s death the dynasty was weakened by dynastic rivalry with the Uí Chennselaig, from whom the Uí Dúnlainge had captured the Kingship of Leinster, and incursions from the Vikings in Dublin. Domnall Claen mac Lorcáin, who had according to the Annals of Ulster “deceitfully killed” Murchad mac Finn in 972 was taken prisoner in 978 by the Danes of Dublin and had to be freed by the intervention of former High King Máel Sechnaill.
After he was killed by the Uí Chennselaig in 984 his son Donchada assumed the kingship and began a nine year rivalry with his Uí Fáeláin rival, Máel Mórda mac Murchada and the Vikings of Dublin.