In his reign Tara was cursed by St.Rodanus of Lothra, in Tipperary, in punishment for violation of sanctuary;[170] and so complete was its subsequent desertion, that in 975 it was described as a desert overgrown with grass and weeds.
But enough still remains to give ample evidence of its former magnificence.

An inspection of the site must convince the beholder of the vast extent of its ancient palaces; nor can we, for a moment, coincide with those who are pleased to consider that these palaces consisted merely of a few planks of wood, rudely plastered over, or of hollow mounds of earth.

It is true that, from an association of ideas, the cause of so many fallacies, we naturally connect "halls" with marble pavements, magnificently carved pillars, and tesselated floors; but the harp that once resounded through Tara's halls, may have had as appreciating, if not as critical, an audience as any which now exists, and the "halls" may have been none the less stately, because their floor was strewn with sand, or the trophies which adorned them fastened to walls of oak.[171] According to Celtic tradition, as embodied in our annals, Tara became the chief residence of the Irish kings on the first establishment of a monarchical government under Slainge:-- "Slaine of the Firbolgs was he by whom Temair was first raised." One hundred and fifty monarchs reigned there from this period until its destruction, in 563.

The _Fes_, or triennial assembly, was instituted by Ollamh Fodhla.

The nature of these meetings is explained in a poem, which Keating ascribes to O'Flynn, who died A.D.984.