Regular clerks are by their institute clerics and priests, and they are devoted to some particular work or works as their own special object - as education, the preaching of missions and retreats, or the going on missions to the heathen.
The fertile low grounds on the east have offered facilities for the invasions of Romans, Norsemen and English, while the mountain fastnesses of the interior and the west have served as secure retreats for the older Celtic population.
He was zealous for the establishment of religious communities, both of men and women, and for the holding of retreats and missions.
From June to August the north west wind blows over the entire area; in September it retreats again as far as 16° N., south of which the winds are for a time variable.
The settlements on Inishmurray (Sligo), Aranmore in the South Arans, and Scattery in the Shannon estuary, had a fame as retreats of piety and learning far outside Ireland itself, and the significance of a:pilgrimage to their sites is not yet wholly forgotten among the peasantry, while the preservation of their remains has come to be a national trust.