Heroic tales, romances, and sagas made up a major part of early Irish literature. This tradition was originally oral, and there were schools to train the filidh (poets), whose responsibilities involved both memorising the stories of past times and composing new poems and stories for current events. This early literature told tales of gods, heroes, kings and chieftains, great deeds, bloody wars, tragic romances, banquets, floods, giants, monsters, transformations, and voyages to imaginary western islands. Many are comparable to modern science fiction. The stories were passed down from generation to generation over several hundred years and were no doubt added to and exaggerated with each generation.
Following the C5th establishment of Christianity, Irish monks adopted the Latin alphabet to write down stories that had been passed down orally for many generations. They generally justified preserving pagan literature by giving the tales an often very superficial connection to Christian stories and beliefs.
The earliest known written Irish stories that survive are in the Leabhar na h-Uidhre [Book of the Dun Cow] and the Book of Leinster, transcribed by monks of the monastery at Glendalough. The earliest extant copies of these were made in the C12th. They were probably originally committed to writing in about the C7th, having been passed along by word of mouth for many generations before that. There are hundreds of manuscripts, many of which have not yet been studied. Most were written between the C9th and C12th.
These tales used to be classified according to topic -“Births; Elopements; Adventures; Battles; Feasts; Courtships; Visions; Cattle Raids; Invasions; Destructions; Slaughters; Irruptions; Loves; Expeditions; Caves; Violent Deaths; Sieges; Frenzies”. Later, they were organized into “cycles,” or long series of loosely related stories.
The oldest cycle is preserved in a collection of myths called the Lebor Gabala [Book of Conquests], and describes the original occupation of Ireland by successive supernatural races including the demonic Fomhóire and the Fir Bholg. The last were the magical Tuatha Dé Danann [Tribe of the goddess Danu], divine sorcerers whose presence can still be sensed in the sigh of the wind in remote lakeside forests at dusk. They ceded the temporal plane to the first humans, the Milesians from Iberia, alleged ancestors of the Gaelic kings.
The Cycle of Kings mixes myth with fact and contains the tales of Irish rulers from 300 BC to 700 AD. The stories may have some historical basis. They include stories of a king driven mad and satirical stories about the Church.
The famous Ulster Cycle concerns the exploits of the warrior Cu Chulain and the celebrated Red Branch Knights. The centrepiece of the cycle is the Táin Bó Cuailnge [The Cattle Raid of Cooley], the oldest vernacular epic in western European literature, and Irish mythology’s nearest approach to an epic work like the Iliad. It tells of the raid for the Brown Bull of Ulster by warriors loyal to Queen Maebh of Connacht. The deadly fight between the hero and his childhood friend Ferdia is particularly poignant. The cycle also contains the beautiful legend of the Children of Lir, whose wicked stepmother turned them into swans for 900 years.
Also famous is the Fenian Cycle, with the central figure Fionn MacCumhail (Finn McCool), the leader of the Fianna, a band of mythical Irish warriors. Fionn’s youthful encounter with the Salmon of Wisdom is a great tale. The Colloquy of the Old Men describes the accidental meeting of Saint Patrick and a Fenian warrior named Cailte, who entertains the saint with legends about the courageous deeds of Fenian heroes as the two men wander through the Irish countryside.
Many of Ireland’s legends have links with those of ancient Celtic cultures and other civilisations throughout Europe and beyond. Even though this literature cannot be taken as literal history, it does help us learn about the manners and customs of the aristocracy in those days. And Irish children of the C21st are still enthralled by the stories of Fionn MacCumhaill, Cu Chulain, and a host of other mythical heroes, along with the great romantic tales of Deirdre of the Sorrows, Diarmuid and Grainne and Oisin in Tir na nOg, the land of eternal youth.
The Irish love for storytelling was gradually channelled into stories about the Christian saints and especially their miracles. One famous such story is about how Saint Patrick drove all the snakes out of Ireland. Many saints are portrayed as miracle workers who used their sacred power to banish monsters, cure illnesses, and provide food for the people in time of need. One of the best-loved saints was Saint Brigid, who, as protector of farming and livestock, preserves many of the attributes of the ancient earth goddess, Danu.
In addition to these hagiographies, religious writing included descriptions of visions, sermons, commentaries on the Scriptures, lists of monastic rules, prayers and hymns, and many monks wrote poetry. Surprisingly, there do not appear to have been any dramas written in early Irish literature. The Irish monasteries had scholars of Greek and Latin, so they had certainly been exposed to drama through these languages, but it would seem that they did not write dramas themselves.
From about 1200, professional bards were employed by noble families to celebrate their importance and their great deeds by writing poems about them. Like earlier poets, they were trained in schools where, as well as the intricate meter of Irish poetry, they studied history and genealogy in the form of various annals (e.g. The Annals of Ulster, The Annals of Connacht, The Annals of Lough Cé, The Annals of Inisfallen, The Annals of Clonmacnoise, etc.). The Annals of the Kingdom of Ireland, Annála Ríoghachta Éireann, or The Annals of the Four Masters as they are commonly known, were compiled from such sources between 1632 and 1636. Geoffrey Keating wrote his History of Ireland around the same time. Traditional Irish Gaelic culture was falling apart by the early C17th, and these were the last major works to be written in Irish until the C19th Gaelic Revival. Much of the information is these pseudo-historical annals cannot be independently checked, but the eighteen specific mentions of the dates of eclipses and comets in the Annals of Ulster have been found to be surprisingly accurate.
It has been suggested that ancient Ireland was the origin of the legend of Atlantis, referred to by Plato.