Medieval Irish historical tradition held that Ireland had been ruled by an Ard Rí or High King since ancient times, and compilations like the 11th-century Lebor Gabála Érenn, followed by early modern works like the Annals of the Four Masters and Geoffrey Keating's Foras Feasa ar Éirinn, purported to trace the line of High Kings. The corpus of early Irish law does not support the existence of such an institution, and scholars now believe it is a pseudohistorical construct of the eighth century AD, a projection into the distant past of a political entity which did not become a reality until the Normans. Rulers like Máel Sechnaill mac Máele Ruanaid declared themselves as King of All Ireland but such claims did not gain the political support of other kingdoms (i.e. Munster), the Norse and Norse-Gaels and was unable to maintain peace with his own Uí Néill kinsmen. The traditional list of High Kings of Ireland is thus a mixture of fact, legend, fiction, and propaganda. The individuals appearing prior to the fifth century AD are generally considered legendary, and the application of the title to individuals before the ninth century is considered anachronistic.
The annalists frequently describe later high kings as rígh Érenn co fressabra ("Kings of Ireland with Opposition"), which is a reference to the instability of the kingship of Tara from the death of Máel Sechnaill mac Domnaill in 1022. Máel Sechnaill had been overthrown by Brian Boru in 1002, and restored in 1014 following Brian's death, but the example of Brian's coup was followed by numerous other families in the century following 1022, and the High Kingship was effectively ended by the Norman quasi-conquest of Ireland in 1171.
Who him ,lol?
Es Lebor Gabála Érenn, por supuesto, lol !!!
ofc it is lol.