Mythological Cycle

The Mythological Cycle is a conventional grouping within Irish mythology. It consists of tales and poems about the god-like Tuatha Dé Danann, who are based on Ireland's pagan deities, and other mythical races such as the Fomorians and the Fir Bolg. It is one of the four main story 'cycles' of early Irish myth and legend, along with the Ulster Cycle, the Fianna Cycle and the Cycles of the Kings. The name "Mythological Cycle" seems to have gained currency with Arbois de Jubainville c. 1881–1883. James MacKillop says the term is now "somewhat awkward", and John T. Koch notes it is "potentially misleading, in that the narratives in question represent only a small part of extant Irish mythology". He prefers T Ó Cathasaigh's name, Cycle of the Gods. Important works in the cycle are the Lebor Gabála Érenn ("Book of Invasions"), the Cath Maige Tuired ("Battle of Moytura"), the Aided Chlainne Lir ("Children of Lir") and Tochmarc Étaíne ("The Wooing of Étaín").

The characters appearing in the cycle are essentially gods from the pre-Christian pagan past in Ireland. Commentators exercising caution, however, qualify them as representing only "godlike" beings, and not gods. This is because the Christian scribes who composed the writings were generally (though not always) careful not to refer to the Tuatha Dé Danann and other beings explicitly as deities. The disguises are thinly veiled nonetheless, and these writings contain discernible vestiges of early Irish polytheistic cosmology.

Examples of works from the cycle include numerous prose tales, verse texts, as well as pseudo-historical chronicles (primarily the Lebor Gabála Érenn (LGE), commonly called The Book of Invasions) found in medieval vellum manuscripts or later copies. Some of the romances are of later composition and found only in paper manuscripts dating to near-modern times (Cath Maige Tuired and The Fate of the Children of Tuireann).

Near-modern histories such as the Annals of the Four Masters and Geoffrey Keating's History of Ireland (=Seathrún Céitinn, Foras Feasa ar Éirinn) are also sometimes considered viable sources, since they may offer additional insights with their annotated and interpolated reworkings of Lebor Gabála Érenn accounts.

Orally transmitted folk-tales may also be, in a broad sense, considered mythological cycle material, notably, the folk-tales that describe Cian's tryst with Balor's daughter while attempting to recover the bountiful cow Glas Gaibhnenn.

The god-folk of the successive invasions are "euhemerised", i.e., described as having dwelt terrestrially and ruling over Ireland in kingship before the age of mortal men (the Milesians, or their descendants). Afterwards, the Tuatha Dé Danann are said to have retreated into the sídhe (fairy mounds), cloaking their presence by raising the féth fiada (fairy mist). Having disappeared but not died, the deities oftentimes make "guest appearances" in narratives categorised under other cycles. (e.g., Lugh's appearance as the divine father and Morrígan as nemesis to the Ulster hero Cuchulainn; encounters of Finnian characters with dwellers of the sidhe; Cormac mac Airt's, or his grandfather's visits to the otherworldly realms.)

Collected literature, while they do not belong to the cycle in entirety, nevertheless capture tidbits of lore about the deities.

The following table is a summary of titles of all of the mythological texts that survive and are in print.^{[citation needed]}