Due to a lack of extensive written historical records prior to the 5th century AD, the early history of Meath is murky and largely mythologised. Irish legend purports that the title of "High King of Ireland" stretches back millennia, however it is today known that the Hill of Tara did not become a seat of power until the early centuries AD. In the 400s, Niall of the Nine Hostages, King of the Uí Néill, conquered southward from Ulster and established a kingdom in Meath. As was commonplace in Ireland at the time, the achievements of Niall and his sons were propagandised and mythicised by bards to such an extent that much of what is known about them is considered fictional. Nevertheless, the dynasty of the Uí Néill had become firmly established in the centre of Ireland and they proclaimed themselves the Kings of Tara and Kings of Uisnech. The Uí Néill dynasty subsequently divided into two septs, the Northern Uí Néill who remained in Ulster, and the Southern Uí Néill who now ruled over several small, disjointed kingdoms established throughout modern-day Meath, Westmeath and Dublin.