The name recurs much later, in Adamnan's Life of Columba, in the name of a wood near Londonderry, Daire-Calgaich or Roboretum Calgachi, "the wood of Calgacus": it may be Celtic and denote "the man with the sword."
Boisguilbert's works were collected by Daire in the first volume of the Collection des grands economistes.
On his return he founded the church and monastery of Armagh, the site of which was granted him by Daire, king of Oriel, and it is probable that the see was intended by him to be specially connected with the supreme ecclesiastical authority.
Of the Principaux economistes, published by Guillaumin, Paris, with preface and notes by Eugene Daire; also his CEuvres economiques et philosophiques were collected with an introduction and note by Aug.
During his residence in Ireland he founded, in addition to a number of churches, two famous monasteries, one named Daire Calgaich (Derry) on the banks of Lough Foyle, the other Dair-magh (Durrow) in King's county.