Díarmait

Díarmait ua Duibne or Diarmaid O'Dyna was the son of Donn and the foster son of Angus Óg. Díarmait was one of the warriors and companions of Finn Mac Cumhaill. In the Acallam na Senórach, Caílte called Díarmait his foster-brother.

Before he was born, his father had killed the son of his wife and her lover, Roc, steward of Angus Óg. Roc resurrected his son, but the boy was transformed into a wild boar. Roc ordered the boar to find and kill Díarmait.

As a Fian warrior, Angus Og and Manannán Mac Lir gave Diarmait some formidable weapons. Diarmait used the Gáe Dearg or Gáe Derg, "red spear", and his sword Nóralltach, "Great Fury", for adventures which are matters of life and death. Diarmait also had the smaller "yellow spear", called Gáe Buide, and a sword named Begallta ("Little Fury") for lesser adventures.

Díarmait was often called Díarmait Ó Duibhne ("Díarmait of the Love Spot"), because one of the beautiful maidens (Danann?) placed a mark on his forehead, making the young hero irresistible to women. This mark would prove to be his undoing.

Gráinne (Grainne), daughter of the Cormac Mac Airt, high king of Ireland, was betrothed to Finn. Grainne preferred young Díarmait to the older Fianna captain. Grainne tried to seduce Díarmait, but he refused her advances until she placed a geis upon the hero. Díarmait was left without a choice and eloped with her.

Finn, learning of the news, tried to hunt them down. Some of Diarmait's adventures included killing the three venomous hounds of the three sea-champions, and slaying the Searbhan (Sharvan), the guardian of the magic rowan tree (quicken tree). For sixteen years they managed to evade Finn's men, before Angus and Cormac persuaded Finn to make peace with the young couple. It was an uneasy peace, and Finn resented Díarmait for taking away his young bride. He never forgave the younger man. By then, Díarmait was the father of four sons and a daughter.

One day, Díarmait heard that the Fianna were hunting for a magic boar that roamed through the forest near Tara. Grainne was unable to convince her husband not to join Finn, knowing that doing so would mean his death.

The boar came upon Díarmait, resistant to the hero's weapons. Díarmait was mortally wounded. Finn, who possessed healing water, allowed the water to slip through his fingers. Díarmait died from his wounds. His body was taken away by Angus Og, his foster father, who preserved his body from decay. It would occasionally be given enough life to talk to Angus.

Grainne swore to avenge her husband's death. She told Finn that when her sons grew to manhood, they would seek the hero and kill him. However, Finn persuaded her to marry him. Grainne felt shamed when the Fian warriors mocked her. In the end, Grainne decided to make peace with Finn.

Díarmait was the hero of several other tales, including freeing Finn and other Fianna who had been trapped in a fairy hostel by killing the Three Kings of the Island of Torrent. See Bruidhean Chaorthainn (Hostel of the Quicken Trees).