Iarbanel. [I] One of the three sons of Nemed who escaped after the defeat and death of their father. His son was Beothach. Iarbanel is said to be the ancestor of the Tuatha De Danaan, while his brother Starn was the ancestor of the Firbolg.

Ibath. [I] Son of Beothach. A Nemedian who fled to Boeotia after the Fomorii had defeated them. He is said to be one of the ancestors of the Tuatha De Danaan.

Ibcan. [I] A son of Beothach.

Iberia. Spain and Portugal. The Iberian peninsula was extensively settled by the Celts, perhaps as early as 900 B.C. Louis Siret [ Questions de cbronologie et d'etbnograpbie iblrique, Paris, 1913] , a founding father of prehistoric archaeology, suggests that the Celts introduced the working of bronze into Spain at the start of the Bronze Age. The first wave of settlers appears to have been Goidelic-speaking. According to Irish mythological traditions, it was from Spain that the Gaels (Goidelic speakers) invaded and colonized Ireland.  The story of Mile Easpain (the Spanish soldier) is recounted in the Leabbar Cabbala (Book of Invasions). It would seem that the Goidelic-speaking settlers in Iberia were replaced in the middle of the first millennium by a fresh wave of Brythonic (Gaulish) speakers, for by the time Greek mariners were establishing their trading posts there the Celtic population had switched languages.  Herodotus (ca. 490-425 B.C.) is the first Greek historian to give a detailed account of the Celts of Iberia, and Aristotle gives the name "Celtica" to the mass of the country. Indeed, Ephoros of Cyme, in the fourth century B.C., indicates that the Celts stretched from the Pyrenees to Gades {Cadiz) in the south.  The end of an independent Celtic Iberia had its roots in the war between Carthage and Rome. In 237 B.C. the Carthaginian general Hamilcar Barca arrived in Iberia and began a systematic reduction of the southwest and southeast coasts. It was from Iberia that Hannibal, son of Hamilcar, decided to launch his attack on Rome through Celtic territory. Without the Celts he would have had little success. With the defeat of Carthage in 197 B.C: to which alliance the Celts firmly clung, Rome began to conquer and colonise the Celts of Spain. Rome's war against the Iberian Celts was marked by an extreme savagery. But actions like those of Servius Sulpicius Galba in 151 B.C:., who massacred the Celts after they had surrendered, caused criticism even in Rome, and Galba was charged with "war crimes" before the Senate. However, the Senate approved of Galba's actions.
It was not until 49 B.C: after a century and a half of continued uprisings and warfare, that peace came to the Celts of Spain. Under more liberal governors, schools had been established for the sons of Celtic chieftains, and the old remnants of Celtic civilisation and tradition were swept away before Latin learning. Soon the Celtiberians were contributing to Latin literature such figures as Marcus Valerius Martialis (Martial) (ca. A.D. 40-103/4), who made a frank assertion of his Celtic identity, and Marcus Fabius Quintilanus (b. A.D. 35), who was the first rhetorician to receive an official salary ftom the Roman state. Egantius, the poet, was an- other Celtiberian whose work was ridiculed in Rome for its Celtic "provincialness." There are many other writers from Spain whose work needs careful analysis, such as the Senecas, Lucan, and Pomponius Mela (whose work on the Celts, especially the druids, preserves information not found elsewhere). According to Publius Tacitus (A.D. 56/57-ca. 117), a Celtic language was still spoken in in any parts of Spain during the first century A.D., but after this there is no mention of a Celtic identity, and the Celts of the Iberian peninsula were, apparently, entirely assimilated. See also Galicia

Ibor. [I] The charioteer who accompanies Cuchulainn during his adventures in "The Boyhood Deeds of Cuchulainn."

Ibor cind trachta. [I] The spot where the goddess Fand arranges her assignation with Cuchulainn; but Emer, Cuchulainn's wife, having discovered this, arrives with 50 maidens carrying sharpened knives to destroy Fand. See Cuchulainn, Emer, and Fand.

Id. [I] Son of Riangabur. He was the charioteer of Conall Cearnach and brother of Cuchulainn's charioteer, Laeg.

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

Ilberg. [I] Son of the sea god Manannin Mac Lir. He ruled the sidhe 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 pe 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.

Ildanach. [I] A title bestowed on Lugh Limhfada 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 berween 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 bodies from one world to another. It is arguable that the Celtic and Pythagorean doctrines were mutually exclusive. See Otherworld.

Indech. [I] A Fomorii warrior, son of the goddess Domnu, who was killed by the god Ogma at the second Battle of Magh Tuireadh.

Ingcel caech. [I] The one-eyed son or grandson of the king of Britain who went in exile to Ireland. He met up with Conaire Mor's three dissident foster brothers and joined forces with them and other Irish dissidents, such as the sons of Ailill and Medb. Together they raided and plundered Ireland and Britain. In Britain they attacked the fortress and destroyed it, killing in the process Ingcel's father, mother, and seven brothers. The final raid of this band was against Da Derga's Hostel, in which the High King, Conaire Mor, was slain. Ingcel was sent to spy on Conaire before the attack.

Invasion Myths.No Celtic "creation myth" has survived. When works about creation began to be written down, the Celts had become Christian and the Hebrew myths of creation had been fully accepted. Therefore, the early myths became an uneasy combination of Hebrew and Celtic mythology, with the Irish tradition claiming descent from Japhet, son of Noah. However, the five invasions of Ireland before the arrival of Mil and his followers (the Gaels) show similarities with the invasion myths of the Indian Rig Veda and demonstrate a closeness to the Indo-European root of Celtic culture. See Invasions, Book of.

Invasions, Book of. [I] Leabhar Gabhdla. The book survives in various ancient manuscripts, mainly in the Book of Leinster twelfth century). It contains the mythical history of Ireland, its creation through the invasions of Cesair, before the Deluge; the invasions of Partholon, Nemed, the Firbolg, the Tuatha De Danaan, and the Milesians. It then follows the subsequent myth/history of Ireland down to the High King MalachaI Mor (A.D. 980-1002). It is regarded as the "national epic" of Ireland. Micheal O Cleirigh (1575-ca. 1645) compiled a version drawn from several ancient manuscripts that are now lost. It is this compilation to which people generally refer when talking about the book.