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.