They became a politically unimportant people, situated between the Dal Messin Corb and the Ui Dega, on the coast of County Wicklow, based around Arklow.
She goes on to state that, by inference of the sources, "the Dál Messin Corb (a branch of the Uí Enechglaiss) was, in fact, dominant in north Leinster in the 5th century and was to the fore in the defence of the province against Coirpre and Ui Neill.
This view is supported by the 'Vita Tripartia', in which Saint Patrick, or more likely Palladius, encountered members of the Uí Garrchon soon after his arrival in Ireland.
The meeting took place in the vicinity of Naas, which is situated in Mag Liphi (the Liffy Plain), then heartland of political power in north Leinster."
The poet Dubhthach moccu Lughair was a native of Gorey, though he lived some sixty years prior to the dynasty's removal to the area.