Diorruing

A Fenian warrior with the gift of clairvoyance. Diorruing was the son of Dobar Ua Baíscne. Diorruing was the friend of Finn Mac Cumhaill.

Diorruing's skill with the second sight enabled him to see the present and the future. In the Pursuit of Diarmait and Gráinne, it was he who advised the aging Finn that the most suitable wife to him would be Gráinne, the daughter of Cormac mac Airt, who was the high king of Ireland.

Diorruing was soon to regret this advice, because Gráinne preferred the younger hero, Diarmait, who was also his friend. When most of the people in her father's court, including her father and Finn, fell into slumber, Gráinne placed a geis upon Diarmait to elope with her. Diarmait was troubled by his misfortune, because he was a great friend of his leader (Finn). Diarmait asked for advice from each of his companions who were not in a drugged stupor, and each one advised that he had to do as Gráinne said because of the geis she had placed on the reluctant hero. Even Cailte Mac Ronan and Finn's own son and grandson, Oisin and Oscar, agreed.

Diorruing, the last companion to advise Diarmait, foretold his friend's death, but he also counselled Diarmait that he must do as Gráinne told him, since the hero was under the geis.