Idath

[I] A warrior from Connacht who marries the goddess Bé Fin, sister of Boann. He is the son of Fraoch, the most handsome warrior in Ireland.

Ilberg

[I] Son of the sea god Manannán Mac Lir. He ruled the sídhe of Eas Aedha Ruaidh, the mount of Mullachshee near Ballyshannon, Co. Donegal. He was also one of the five candidates for the kingship of the Tuatha Dé Danaan when the Dagda announced his intention to give up the role. During the subsequent war between the gods, Ilberg fought for Midir the Proud alongside the contingent of mortals led by Caoilte of the Fianna. Caoilte, however, slew his grandfather, Lir.

Ildánach

[I] A title bestowed on Lugh Lámhfada when he presented himself at the court of Nuada. It means “The All-Craftsman.”

Imbolg

[I] Also given as Imbolc. One of the four great annual pre-Christian festivals, it was sacred to the fertility goddess, Brigid, and held on February 1. See Brigid. It was subsequently taken over by the Christian Church and became St. Brigid’s feast day.

Immortality

The Celts were one of the first European peoples to develop a doctrine of immortality of the soul. The basic belief was that death was only a changing of place and that life went on with all it forms and goods in the Otherworld. A constant exchange of souls was always taking place between the two worlds; death in this world brought a soul to the Otherworld, and death in the Otherworld brought a soul to this world. Philostratus of Tyana (ca. a.d. 170–249) observed that the Celts celebrated birth with mourning and death with joy. Caesar, the cynical soldier, remarked that this teaching of immortality doubtless accounted for the reckless bravery of the Celts in battle. Sotion of Alexandria (ca. 200–170 b.c.) claimed that the Greeks accepted “much of their philosophy” from early contact with the Celts and that Pythagoras taught a doctrine of immortality of the soul based on the Celtic idea. Diodorus Siculus (d. ca. 21 b.c.) reverses the claim, saying the Celts developed the philosophy from Pythagoras. However, the third possibility is that the similarity between the Celtic philosophy and Pythagoras’ philosophy (which is of reincarnation, not an exchange of souls between two worlds) is superficial. Transmigration of souls through all living things, as taught by Pythagoras, was not the Celtic idea. The Celtic belief was in rebirth of the soul in human