Early Irish literature in the context of "Irish mythology"

Gaelic Ireland (Irish: Éire Ghaelach) was the Gaelic political and social order, and associated culture, that existed in Ireland from the late prehistoric era until the 17th century. It comprised the whole island before Anglo-Normans conquered parts of Ireland in the 1170s. Thereafter, it comprised that part of the country not under foreign dominion at a given time (i.e. the part beyond The Pale). For most of its history, Gaelic Ireland was a "patchwork" hierarchy of territories ruled by a hierarchy of kings or chiefs, who were chosen or elected through tanistry. Warfare between these territories was common. Traditionally, a powerful ruler was acknowledged as High King of Ireland. Society was made up of clans and, like the rest of Europe, was structured hierarchically according to class. Throughout this period, the economy was mainly pastoral and money was generally not used. A Gaelic Irish style of dress, music, dance, sport and art can be identified, with Irish art later merging with Anglo-Saxon styles to create Insular art.

Gaelic Ireland was initially pagan and had an oral culture maintained by traditional Gaelic storytellers/historians, the seanchaidhthe. Writing, in the form of inscription in the ogham alphabet, began in the protohistoric period, perhaps as early as the 1st century. The conversion to Christianity, beginning in the 5th century, accompanied the introduction of literature. In the Middle Ages, Irish mythology and Brehon law were recorded by Irish monks, albeit partly Christianized. Gaelic Irish monasteries were important centres of learning. Irish missionaries and scholars were influential in western Europe and helped to spread Christianity to much of Britain and parts of mainland Europe.

Vernacular literature is literature written in the vernacular—the speech of the "common people".

In the European tradition, this effectively means literature not written in Latin or Koine Greek. In this context, vernacular literature appeared during the Middle Ages at different periods in the various countries; the earliest European vernacular literatures are Irish literature (the earliest being Tochmarc Emire (10th century), transcribed from a lost manuscript of the 8th century), Welsh literature, English literature and Gothic literature.

Táin Bó Cúailnge (Modern Irish pronunciation: [ˈt̪ˠaːnʲ bˠoː ˈkuəlʲɲə]; "the driving-off of the cows of Cooley"), commonly known as The Táin or less commonly as The Cattle Raid of Cooley, is an epic from Irish mythology. It is often called "the Irish Iliad", although like most other early Irish literature, the Táin is written in prosimetrum, i.e. prose with periodic additions of verse composed by the characters. The Táin tells of a war against Ulster by Queen Medb of Connacht and her husband King Ailill, who intend to steal the stud bull Donn Cuailnge. Due to a curse upon the king and warriors of Ulster, the invaders are opposed only by the young demigod, Cú Chulainn.

The Táin is traditionally set in the 1st century in a pagan heroic age, and is the central text of a group of tales known as the Ulster Cycle. It survives in three written versions or "recensions" in manuscripts of the 12th century and later, the first a compilation largely written in Old Irish, the second a more consistent work in Middle Irish, and the third an Early Modern Irish version.

Samhain (/ˈsɑːwɪn/ SAH-win, /ˈsaʊɪn/ SOW-in; Irish: [ˈsˠəunʲ]; Scottish Gaelic: [ˈs̪ãũ.ɪɲ]) or Sauin (Manx: [ˈsoːɪnʲ]) is a Gaelic festival on 1 November marking the end of the harvest season in autumn and beginning of winter or the "darker half" of the year. It is also the Irish and Scottish Gaelic name for November. Celebrations begin on the evening of 31 October, since the Celtic day began and ended at sunset. This is about halfway between the autumnal equinox and winter solstice. It is one of the four Gaelic seasonal festivals along with Imbolc, Bealtaine, and Lughnasa. Historically it originated in Ireland and it was widely observed throughout Ireland, Scotland, and the Isle of Man. Its Brittonic Celtic equivalent is called Calan Gaeaf in Wales.

Samhain is believed to have Celtic pagan origins, and some Neolithic passage tombs in Great Britain and Ireland are aligned with the sunrise at the time of Samhain. Samhain is mentioned in the earliest Irish literature, from the 9th century, and is associated with many important events in Irish mythology. The early literature says Samhain was marked by great gatherings and feasts and was when the ancient burial mounds were open, which were seen as portals to the Otherworld. Some of the medieval tales also associate Samhain with bonfires and sacrifice.

Imbolc or Imbolg (Irish pronunciation: [ə ˈmˠɔlˠəɡ]), also called Saint Brigid's Day (Irish: Lá Fhéile Bríde; Scottish Gaelic: Là Fhèill Brìghde; Manx: Laa'l Breeshey), is a Gaelic traditional festival on 1 February. It marks the beginning of spring, and in Christianity, it is the feast day of Saint Brigid, Ireland's patroness saint. Historically, its many folk traditions were widely observed throughout Ireland, Scotland and the Isle of Man. Imbolc falls about halfway between the winter solstice and the spring equinox and is one of the four Gaelic seasonal festivals, along with Bealtaine, Lughnasadh and Samhain.

Imbolc is mentioned in early Irish literature, although less often than the other seasonal festivals. Historians suggest that Imbolc was originally a pre-Christian (or pagan) festival associated with the lambing season, the coming of spring, and possibly the goddess Brigid, proposing that the saint and her feast day might be Christianizations. A feast of Saint Brigid was first mentioned in the Middle Ages, but its customs were not recorded in detail until the early modern era. In recent centuries, Brigid's crosses have been woven on St Brigid's Day and hung over doors and windows to protect against fire, illness, and evil. People also made a doll of Brigid (a Brídeóg), which was paraded around the community by girls, sometimes accompanied by 'strawboys'. Brigid was said to visit one's home on St Brigid's Eve. To receive her blessings, people would make a bed for Brigid, leave her food and drink, and set items of clothing outside for her to bless. Holy wells would be visited, a special meal would be had, and the day was traditionally linked with weather lore.

The gods and goddesses of the pre-Christian Celtic peoples are known from a variety of sources, including ancient places of worship, statues, engravings, cult objects, and place or personal names. The ancient Celts appear to have had a pantheon of deities comparable to others in Indo-European religion, each linked to aspects of life and the natural world. By a process of syncretism, after the Roman conquest of Celtic areas, most of these became associated with their Roman equivalents, and their worship continued until Christianization. Epona was an exception and retained without association with any Roman deity. Pre-Roman Celtic art produced few images of deities, and these are hard to identify, lacking inscriptions, but in the post-conquest period many more images were made, some with inscriptions naming the deity. Most of the specific information we have therefore comes from Latin writers and the archaeology of the post-conquest period. More tentatively, links can be made between ancient Celtic deities and figures in early medieval Irish and Welsh literature, although all these works were produced well after Christianization.

The locus classicus for the Celtic gods of Gaul is the passage in Julius Caesar's Commentarii de Bello Gallico (The Gallic War, 52–51 BC) in which he names six of them, together with their functions. He says that Mercury was the most honoured of all the deities and many images of him were to be found. Mercury was regarded as the inventor of all the arts, the patron of travellers and of merchants, and the most powerful deity in matters of commerce and gain. After him, the Gauls honoured Apollo, who drove away diseases, Mars, who controlled war, Jupiter, who ruled the heavens, and Minerva, who promoted handicrafts. He adds that the Gauls regarded a god he likened to Dis Pater as their ancestor.

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").