List of High Kings of Ireland

Medieval Irish historical tradition held that Ireland had a High King (Ard Rí) based at Tara 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 Foras Feasa ar Éirinn, purported to trace the line of High Kings. John T. Koch explains: "Although the kingship of Tara was a special kingship whose occupants had aspirations towards supremacy among the kings of Ireland, in political terms it is unlikely that any king had sufficient authority to dominate the whole island before the 9th century".

Source: Wikipedia — List of High Kings of Ireland (CC BY-SA 4.0)