Desi. [I] Sometimes given as the decies. A clan of Bregia in the province of Mide. The clan features in the tale "The Expulsion of the Desi," which is stylistically dated to the third century by Professor Kuno Meyer. For disfiguring Cormac Mac Art, Aonghus of the Terrible Spear and his tribe, the Desi, are expelled from their lands. Some settle in Munster, the rest are pursued from Ireland and, after a voyage of many adventures, settle in Dyfed in Wales. The Desi settlement is a historical one. There is an Ogham inscription, surviving in the Carmarthen Museum, dated to the sixth century A.D. It is to Voteocorigas, a Desi ruler, who is believed to be the Voterporius whom Gildas attacks as a tyrant.

Dian Cecht. [I] The god of medicine. After Nuada lost his hand at the first battle of Magh Tuireadh, Dian cecht supplied him with a silver hand. Miach, Dian cecht's son, proved a better physician by eventually supplying Nuada with a flesh and blood hand. Miach actually did an eye transplant, replacing a human eye with that of a cat. In jealousy, Dian Cecht slew his son. Among the Brehon law tracts is one called "The Judgments of Dian cecht," relating to the practise of medicine, which Professor Binchey dates as early as the sixth century A.D. [Eriu, Vol. XX].

Diarmuid. [I] There are three notable Diarmuids in Irish myth: a king whose wife, Bec Fola, visits the Otherworld; a son of Fergus Cearbaill who is cursed by St. Ronin; and, lastly, most famous of all, is Diarmuid Ua Duibhne (Of the Love Spot), the most handsome warrior of the Fianna. Grainne, who is about to wed Fionn Mac Cumhail, persuades Diarmuid to elope with 'her and thus begins the most famous chase, "The Pursuit of Diarmuid and Grainne," which lasts sixteen years. While Diarmuid is not exactly in love with Grainne at the start, he does grow to love this capricious woman of the myths. When the love god Aonghus Og and the High King eventually persuade Fionn Mac Cumhail to make his peace with them, Fionn still nurses a grudge. Out hunting on Ben Bulben, Diarmuid meets his fate in the form of a magic boar. This is the child of Roc, Aonghus Og's steward, by Diarmuid's own mother. Diarmuid's father, Donn, learning of his wife's affair with Roc and discovering the child, kills it. Roc, however, transforms the dead child into a great boar and orders it to bring about the death of Donn's son, Diarmuid. The boar now fulfils its destiny by goring Diarmuid. Mortally wounded, only Fionn can save him. But he does not and Diarmuid dies. Diarmuid's grandfather, the love god Aonghus Og, takes the body to Bruigh na Boinne and each day he sends a soul into the body so that he might talk with Diarmuid. But this "resurrection" is only for a few moments each day. Fionn eventually succeeds in his ambition to marry Griinne.

Dinas Emrys. [W] A hill fort at Bedgelert associated with Vortigern, according to Nennius. The fort is named after Emrys (Ambrosius), who overthrew Vortigern. Certainly, although mainly constructed in the pre-Roman period, defences were built here in the fifth and sixth centuries A.D. It is now dominated by a twelfth century tower. Dinnsenchas. [I] "The lore of prominent places." A comprehensive topography of Ireland and a guide to geographical mythology. It is contained in the twelfth centuryBook of Leinster.

Dinodig. [W] The land over which Lieu and Blodeuwedd ruled.

Dis Pater. The Gaulish god whose Celtic name is not revealed by Caesar. "The Gauls all claim to be descended from Dis Pater, and say that this is the teaching of the druids. For this reason they measure the passage of time not by days but by nights." This would indicate that the Dis Pater was not a purely chthonic deiry but reigned in the Otherworld and was compared to the Roman Pluto.  The idea of common descent from an ancestor was essential to Celtic ideology. The analogous god to the Dis Pater in Irish mythology is thought to be Donn, while others regard him as identical with The Dagda.

Dissull. [W] A giant, the hair of whose beard could create the only leash for the dogs in the hunting pack that Mabon controls in the hunt for Twrch Trwyth. Cai and Bedwyr overcome him and pluck out his beard.

Divination. The art of foretelling the future is an essential part of the Celtic myths. In most cases the hero or heroine has his or her fate foretold at birth. Such was the case of Deirdre, whose horoscope was cast by Cathbad the druid. More often than not it is in an effort to escape their fate that the protagonists set out on the adventures that will eventually lead them to the very fate they seek to avoid. In some cases, particularly in the Irish tales, the fate seems unlikely, but circumstances always contrive to make it so. The art of divination was widely practised in all Celtic societies and came in many forms-astrology, dreams, signs and omens from nature, and unusual occurrences. One form was the casting of yew wands inscribed with mystic words in Ogham. Divination was the prerogative of the druids, both male and female. See Astrology.

Diwrnach. [W] An Irishman, owner of a magic cauldron that Arthur manages to loot in. a trip to Ireland.

Domnu. [I]. Goddess of the Fomorii. The name seems to signify the abyss of the sea; the Fomorii, of course, translates as "undersea dwellers." Domnu appears to be a mother goddess and ancestor of all the Fomorii. The theme of many sagas is the struggle berween the Children of Domnu (representing darkness and evil} and the Children of Dana (representing light and goodness}. Don. .[W] Welsh equivalent of Danu, the "mother goddess." The fourth branch of the Mabinogion introduces'the children of Don, who include Gwydion and Gilfaethwy, sons of Don, and Aranrhod, daughter of Don. She is given as the daughter of Mathonwy and is therefore sister of Math. She marries Beli, god of death, son of Manogan. Their children are Gwydion (science and light), Aranrhod (dawn goddess), Gilfaethwy, Amaethon (agriculture), Gofannon (smith-craft), Nudd or lIudd (sky god), Penardun (wife to lIyr), Nynniaw, and Peibaw. From Gwydion and his sister Aranrhod come Nwyfre (space), lIeu Llaw (the sun god), and Dylan (sea god), while Nudd's son Gwyn is the keeper of the Otherworld (Annwn) .  Don is regarded as a bye form of Donwy, which occurs in Wales in the river names Dyfrdonwy and Trydonwy. The name is cognate with the goddess Danu in Irish and in the Rig Veda, where the name signifies "waters ofheaven"-there are several rivers throughout the form~r Celtic world that bear her name. In England the rivers Don in Durham and Yorkshire are derived from her, while the name is also cognate with the Danube.

Donn. [I] There are several people who bear the name in Irish mythology, but the most important one is the god of the dead, whose abode was at Tech Duinn (House of Donn), which is placed on an island off the southwest of Ireland. He is said to be the eldest son of Midir the Proud. Another important Donn was the eldest son of Milesius, whose tradition is somewhat mixed with the god of the dead. His doom was foretold by the goddess Eire because he ignores her wish that Ireland be named after her. He drowns in the sea during an invasion. The father of Diarmuid Ua Duibhne was also named Donn, while the famous Brown Bull of Cuailgne is called Donn Cuailgne.

Dormath. [W] The hound of Gwyn ap Nudd. The name appears to mean "door of death."

Dragons.These mythical beasts, which are found in the mythology and folklore of innumerable peoples, likewise abound in Celtic mythology. Sometimes they guard palaces or fortresses, mostly they live at the bottom of lakes. In the story of "lIudd and lIefelys," a dragon has to be encountered, and Fraoch fought a dragon. Throughout the Celtic world dragons are a traditional motif and a dragon was displayed on the war banner of Macsen Wledig. This is thought to be the origin of the red dragon banner of Wales, Arthur's father, in later tradition, becomes Uthr Pendragon (pen meaning "head"or "chief"