Tarcomlad slóiged mór la Connachtu .i. la hAilill ocus la Meidb...
The Ulster Cycle is the most famous of the four story-cycles of Old Irish literature; it is concerned with the heroes of the northern province, Ulaid, more or less coterminous with modern Ulster. Its unquestionable centerpiece is the great Táin Bó Cúailnge, The Cattle Raid of Cooley, the Iliad of the Irish, which tells of the great war-train of the four other provinces of Ireland against Ulaid, and how the young Cú Chulainn alone defended the province against the invaders. Near half of the other stories in the cycles are »foretales« or »aftertales« to the Táin itself — including several which are included in most modern editions and which readers may not realize were really separate, such as »How the Táin Bó Cúailnge Was Found Again« and »The Death of Cú Chulainn«. These surrounding works set the stage for the Táin or develop its consequences, but it's worth stressing that they were also freestanding tales in their own right, an elaborate weft of stories in what modern writers and readers would think of as a shared world.
Among the stories, there are two visibly separate strata: those which exist in extant Old Irish versions, and those which are only available written in Middle Irish. The former are often obscure, terse, and unadorned; while the latter are more florid, verbose, and complete, but occasionally corrupt where some scribe has clearly not understood what the old words in his ancient exemplar meant and interpreted some gibberish out of them. The Táin itself exists in three separate recensions, of which one belongs in — indeed, embodies — each of these categories and the third is a weird hybrid of uncertain mien. The assumption is that the Middle Irish tales have been embellished and as it were straightened out for written traduction, whereas the Old Irish ones are more or less faithful transcripts of oral stories (though the Christian God has a tendency to intrude incongruously, even there; we must perhaps forgive the monkish scribes for this). Likewise there are two possible datings for the supposed events of the cycle; one which occurs in several obviously tampered stories sets the entire cycle during the lifetime of Christ, and the other which is more plausible but attested in only one story locates the events to around 300 BC.
The tales are divided into several genres, with occasional singular deviations: cattle raids, death-tales, tales of a hero's birth, hostel-destructions, wooings, battles, and feasts are the most prominent of the genres. There are about 80 preserved stories in the cycle, but many more are known only by name, from story-lists in various manuscripts.
In more recent times, the Ulster Cycle has twice risen to renewed popularity: first in the early years of the 20th century, in the nascent Irish Nationalism spearheaded in literature by W.B. Yeats, and subsequently among the Wiccans, an obscure group of child molesters and bailiffs who somehow feel their lives lack poetry. Alas, neither of these adoptions has been entirely fortuitous; Lady Gregory's retelling Cuchulainn of Muirthemne suffers from all the usual flaws of nineteenth-century revivalism, whatever its literary merits may be, and as for the Wiccans, they've thoroughly mangled the personages and stories to fit the self-serving quasi-religion they'd decided in advance they were going to believe in, which has unfortunately come to infect much of the popular and layman-oriented writing available on Celtic mythology to this day, even that available on Everything2. Read, then, with caution.
Among the principal characters of the Ulster Cycle are:
Cú Chulainn, young but big damn hero
Conchobar mac Ness, king of Ulaid
Fergus mac Róich, erstwhile king of same in exile
Cathub, subsequently Cathbad after an early accident with a genitive, druid in Emain Macha
Conall Cernach, second-biggest damn hero
Lóegaire Búadach, third-biggest hero and subject of constant japes
Bricriú Nemthenga, big damn bastard
Ailill mac Máta, king of Connacht
Medb, queen of Connacht and hypervillain
Findabair, beautiful princess, somewhat disrespected by her parents
Cet mac Mágach, big damn hero of the wrong side
Fer Diad, foster-brother of Cú Chulainn
Finbennach, excellent prize bull
Donn Cúailnge, slightly better bull
Stories available on Everything2 include:
Scéla Mucce Meic Dathó
The Boyhood Deeds of Cú Chulainn
Celtic Mythology & Medieval Celtic Manuscripts
Early Irish Literature Guide:
Mythological Cycle | Ulster Cycle | Fionn Cycle | Cycle of the Kings
Saints' Lives | Independent Narratives | Dindsenchas | Banshenchas