Callaghan of Cashel was, perhaps, as brave, but his name cannot be held up to the admiration of posterity.

The personal advancement of the southern Hy-Nials was more to him than the political advancement of his country; and he disgraced his name and his nation by leaguing with the invaders.

In the year 934 he pillaged Clonmacnois.

Three years later he invaded Meath and Ossory, in conjunction with the Danes.

Muircheartach was several times on the eve of engagements with the feeble monarch who nominally ruled the country, but he yielded for the sake of peace, or, as the chroniclers quaintly say, "God pacified them." After one of these pacifications, they joined forces, and laid "siege to the foreigners of Ath-cliath, so that they spoiled and plundered all that was under the dominion of the foreigners, from Ath-cliath to Ath-Truisten."[206] In the twenty-second year of Donough, Muircheartach determined on a grand expedition for the subjugation of the Danes.