The term King of Tara was a title of authority in ancient Ireland. The position was considered an eminent authority in medieval Irish literature and mythology, though national kingship was never a historical reality in early Ireland.
The title King of Tara represented a very old ideal of sacred kingship in Ireland, imbued with mythical aura stretching back deep into the long-forgotten past, even from the perspective of its earliest historical holders. For these reasons holding the title King of Tara invested the incumbent to a powerful status, perhaps as an almost totally forgotten tradition of a sacred king of kings, barely remembered yet retained by unknowing tradition. Many so-called Irish High Kings were simultaneously Kings of Tara, and in later times actual claimants to this new title (which only emerged in the ninth and tenth centuries) used their initial position as King of Tara to promote themselves in status and fact to the High-Kingship. Prior to this, various branches of the Uí Néill dynasty appear to have used it to denote overlordship of their kindred and realms.
Therefore, it should be realised that for much of history, the titles King of Tara and High King of Ireland were distinct and unrelated.
The following is a list of those accorded the title (or at least believed to be seated) in the Irish annals, king lists and legends. The dates and names of the early kings are uncertain and often highly suspect. Several may be doubles of others or composite characters, and also assigned to the wrong prehistoric kindreds.