Others have surmised that it was abandoned as a regular place of residence long before this, soon after the northern and southern branches of the Hy Neill had consolidated their power at Ailech and in Westmeath.
The oscillation of the centre of power between Meath and Tir Eogain, according as the ardri belonged to the southern or northern Hy Neill, produced corresponding perturbations in the balance of parties among the minor kings.
He applied to the northern Hy Neill to come to his assistance, and even offered to abdicate in favour of the chief of the Cinel Eogain, but the latter refused unless Maelsechlainn undertook to cede to them half the territory of his own tribe, the Cland Colmain.
In 679 he was elected abbot of Hy or Iona, being ninth in succession from the founder, St Columba.
This victory, won over the combined forces of the Scandinavians of Dublin, Man and the Isles, compelled Amlaib to deliver up all his captives and hostages, - among whom were Domnall Claen, king of Leinster, and several notables - to forgo the tribute which he had imposed upon the southern Hy Neill and to pay a large contribution of cattle and money.
Four of his sons, Loigaire, Conall Crimthand, Fiacc and Maine, settled in Meath and adjoining territories, and their posterity were called the southern Hy Neill.
Travelling generally in companies, and carrying a simple outfit, these Celtic pioneers flung themselves on the continent of Europe, and, not content with reproducing at Annegray or Luxeuil the willow or brushwood huts, the chapel and the round tower, which they had left behind in Derry or in the island of Hy (Iona), they braved the dangers of the northern seas, and penetrated as far as the Faroes and even far distant Iceland.
Diarmait MacMurchada (Dermod MacMurrough), greatgrandson of Diarmait Mael-na-mBo, as king of Leinster was by descent and position much mixed up with foreigners, and generally in a state of latent if not open hostility to the high-kings of the Hy Neill and Dalcais dynasties.
The tanists or heirs of the northern and southern Hy Neill having died, the throne fell to Maelsechlainn II., of the Cland Colrnain, the last of the Hy Neill who was undisputed king of Ireland.
However, the effects of Brian's revolution were permanent; the prescriptive rights of the Hy Neill were disputed, and from the battle of Clontarf until the coming of the Normans the history of Ireland consisted of a struggle for ascendancy between the O'Brians of Munster, the O'Neills of Ulster and the O'Connors of Connaught.