The term Celts (pronounced "kelts" or "selts") refers to any of a number of ancient peoples in Europe using the Celtic languages, which form a branch of Indo-European languages, as well as others whose language is unknown but where associated cultural traits such as Celtic art are found in archaeological evidence. Historical theories were developed that these factors were indicative of a common origin, but later theories of culture spreading to differing indigenous peoples have recently been supported by genetic studies.

Though the spread of the Roman empire led to continental Celts adopting Roman culture, the development of Celtic Christianity in Ireland and Britain brought an early medieval renaissance of Celtic art between 400 and 1200. Antiquarian interest from the 17th century led to the term Celt being developed, and rising nationalism brought Celtic revivals from the 19th century in areas where the use of Celtic languages had continued.

Today, "Celtic" is often used to describe the languages and respective cultures of Ireland, Scotland, Wales, Cornwall, the Isle of Man and the French region of Brittany, as many of the people in these regions have Celtic ancestry (see the Modern Celts article), but correctly corresponds to the Celtic language family - in which are still spoken: Scottish, Irish and Manx (Gaelic languages) and Welsh, Breton and Cornish (Brythonic languages).

The Celtic language family is a branch of the larger Indo-European family, which leads some scholars to a hypothesis that the original speakers of the Celtic proto-language may have arisen in the Pontic-Caspian steppes. However, as the Celts enter history from around 600 BC, they are already split into several languages groups, and spread over much of Central Europe, the Iberian peninsula, Ireland and Britain, and studies now suggest that some of the Celtic peoples - including the ancestors of all the modern Celtic nations - had a largely pre-Celtic genetic ancestry, shared with the Basque people and possibly going back to the Palaeolithic.

Some scholars think that the Urnfield culture represents an origin for the Celts as a distinct cultural branch of the Indo-European family. This culture was preeminent in central Europe during the late Bronze Age, from ca. 1200 BC until 700 BC, itself following the Unetice and Tumulus cultures. The Urnfield period saw a dramatic increase in population in the region, probably due to innovations in technology and agricultural practices. The spread of iron-working led to the development of the Hallstatt culture directly from the Urnfield (c. 700 to 500 BC). Proto-Celtic, the latest common ancestor of all known Celtic languages, is thought to have been spoken at the time of the late Urnfield or early Hallstatt cultures, in the early 1st millennium BC.

The spread of the Celtic languages to Britain and to Iberia would have occurred during the first half of the 1st millennium, the earliest chariot burials in Britain dating to ca. 500 BC. Over the centuries they developed into the separate Celtiberian, Goidelic and Brythonic languages. Whether Goidelic and Brythonic are descended from a common Insular-Celtic language, or if they reflect two separate waves of migration is disputed. The La Tene culture, in any case, can be associated with the Gauls, but it is entirely too late for a candidate for the Proto-Celtic culture.

The Hallstatt culture was succeeded by the La Tène culture, and during the final stages of the Iron Age gradually transformed into the explicitly Celtic culture of early historical times. The La Tène culture was distributed around the upper reaches of the Danube, Switzerland, Austria, southern and central Germany, eastern France, Bohemia and Moravia, and parts of Hungary. The technologies, decorative practices and metal-working styles of the La Tène were to be very influential on the continental Celts. The La Tène style was highly derivative from the Greek, Etruscan and Scythian decorative styles with whom the La Tène settlers frequently traded.

Additional forays into Greece and central Italy during the historical period did not result in settlement, though the same movement that brought Celtic invaders to Greece pushed on through to Anatolia, where they settled as the Galatians.

As there is no archaeological evidence for large scale invasions in some of the other areas, one current school of thought holds that Celtic language and culture spread to those areas by contact rather than invasion. However, the Celtic invasions of Italy, Greece, and western Anatolia are well documented in Greek and Latin history.

Stonehenge and the other megalithic monuments long predate the Iron Age Celtic culture, but Genetic evidence indicates that the Celtic populations of the Atlantic Archipelago have been relatively stable for at least 6,000 years, in which case the modern Celts would be the direct descendants of their builders. There is no evidence that they used these sites as areas of worship from the Iron Age on, however, and indeed most evidence suggest that the Druidic Celtic religion(s) preferred to use groves of Oak trees as places of worship. The connection between these monuments and the Celts largely stems from 18th century romantics such as William Stuckeley.

The indigenous populations of Britain and Ireland today are primarily descended from the ancient peoples that have always inhabited these lands. As to their culture, little is known but remnants remain primarily in the naming of certain geographical features, such as the rivers Clyde, Tamar, Thames and Tyne.

By the Roman period most of the inhabitants of the isles of Ireland and Great Britain (the ancient Britons) were speaking Goidelic or Brythonic languages, close counterparts to Gaulish languages spoken on the European mainland. Historians explained this as the result of successive invasions from the European continent by diverse Celtic-speaking peoples over the course of several centuries.

In 1946 the Celtic scholar T. F. O'Rahilly published his extremely influential model of the early history of Ireland which postulated four separate waves of Celtic invaders. What languages were spoken by the peoples Ireland and Britain before the arrival of the Celts is unknown.

Later research indicated that the language and culture had developed gradually and continuously, and in Ireland no archaeological evidence was found for large intrusive groups of Celtic immigrants, suggesting to historians such as Colin Renfrew that the native Late Bronze Age inhabitants gradually absorbed influences to create "Celtic" culture. The very few continental La Tène culture style objects which had been found in Ireland could have been imports, or the possessions of a few rich immigrants.

Julius Caesar had written of people in Britain who came from Belgium (the Belgae), but archaeological evidence which was interpreted in the 1930s as confirming this was contradicted by later interpretations and it was suggested that there might have been only a handful of élite Belgae in Britain.

In the 1970s this model was popularised by Colin Burgess in his book The Age of Stonehenge which theorised that Celtic culture in Great Britain "emerged" rather than resulted from invasion and that the Celts were not invading aliens, but the descendants of the people of Stonehenge.

More recently a number of genetic studies have supported this model of culture being absorbed by native populations. The study by Cristian Capelli, David Goldstein and others at University College, London showed that genes associated with Gaelic names in Ireland and Scotland are also common in Wales, Cornwall and most parts England, and are similar to the genes of the Basque people, who speak a non-Indo-European language.

This similarity supported earlier findings in suggesting a largely pre-Celtic genetic ancestry, possibly going back to the Paleolithic. They suggest that 'Celtic' culture and the Celtic language were imported to Britain by cultural contact not mass invasions, either by Indo-Europeans bringing farming or by Celts in 600 BC.

Some recent studies have suggested that, contrary to long-standing beliefs, the Teuton tribes did not wipe out the Romano-British of England but rather, over the course of six centuries, conquered the native Brythonic people of what is now England and south east Scotland and imposed their culture and language upon them, in a manner similar to the Irish spread over the west of Scotland.

At the dawn of history in Europe, the Celts in present-day France were known as Gauls. Their descendants were described by Julius Caesar in his Gallic Wars. There was also an early Celtic presence in northern Italy. Other Celtic tribes invaded Italy, establishing there a city they called Mediolanum (modern Milan) and sacking Rome itself in 390 BC following the Battle of the Allia. A century later the defeat of the combined Samnite, Celtic and Etruscan alliance by the Romans in the Third Samnite War sounded the end of the Celtic domination in Europe, but it was not until 192 BC that the Roman armies conquered the last remaining independent Celtic kingdoms in Italy.

Under Caesar the Romans conquered Celtic Gaul, and from Claudius onward the Roman empire absorbed parts of the Celtic British Isles. Roman local government of these regions closely mirrored pre-Roman 'tribal' boundaries, and archaeological finds suggest native involvement in local government. Latin was the official language of these regions after the conquests.The native peoples under Roman rule became Romanized and keen to adopt Roman ways. Celtic art had already incorporated classical influences, and surviving Gallo-Roman pieces interpret classical subjects or keep faith with old traditions despite a Roman overlay.

Roman influence lead directly to the decline of the druidic priests. Prior to Roman conquests, the druids exercised enormous spiritual and political power among the celtic peoples. The druidic religion was seen as a major impediment to the "Romanization" of the newly conquered celts. Thus began a deliberate policy on the part of the Roman conquerors to replace the old celtic political structure with Roman institutions. The elimination of the druidic class was instrumental to cementing Roman authority.

This led the birth of many Romano-celtic deities, as old celtic gods took on new latin names and aspects of Roman divinities, and began to be worshipped alongside the more traditional Jovian pantheon.

While the regions under Roman rule adopted Christianity along with the rest of the Roman empire, unconquered areas of Scotland and Ireland moved from Celtic polytheism to Celtic Christianity which was a major source of missionary work in other parts of Britain and central Europe. This brought the early medieval renaissance of Celtic art between 400 and 1200, developing many of the styles now thought of as typically Celtic, and found through much of Ireland and Britain, including the north-east and far north of Scotland, Orkney and Shetland Islands. This was brought to an end by Roman Catholic and Norman influence, though the Celtic languages and some minor influences of the art continued.

Celts were pushed westwards by successive waves of Germanic invaders, perhaps themselves at times pressured by Huns and Scythians or simply population pressures in their homeland of Scandinavia and Northern Germany. With the fall of the Roman Empire the Celts of Gaul, Iberia and Britannia were "conquered" by tribes speaking Germanic languages.

Elsewhere, the Celtic populations were assimilated by others, leaving behind them only a legend and a number of place names such as Bohemia, after the Boii tribe which once lived there, or the Kingdom of Belgium, after the Belgae, a Celtic tribe of Northern Gaul and south-eastern England. Their mythology has been absorbed into the folklore of half a dozen other countries. For instance, the famous Medieval English Arthurian tale of Sir Gawain and the Green Knight is almost certainly partially derived from the medieval Irish text Fled Bricrend (The Feast of Bricriu).

Argument rages in the academic world as to whether the Celts in England were mostly wiped out/pushed west as the lack of evidence for influence of the Celts on Anglo-Saxon society suggests, or whether the Teuton migration consisted merely of the social elite and that the genocide was cultural rather than physical due to such relatively few numbers of Anglo-Saxons mixing with the far larger native population, enabled to do so due to the civil strife in Britain after the Roman withdrawal and the unity of the incoming invaders. Some recent DNA studies have suggested that the population of England maintains a predominately ancient British element, equal in most parts to Cornwall and Wales. The general indigenous population of Yorkshire, East Anglia and the Orkney and Shetland Islands are those populations with the least traces of ancient British continuation. Ironically, it may be Viking genetic influence and not Anglo-Saxon which has had a more profound impact on British bloodlines.

The pre-Christian Celts had a well-organized social structure, based on class and kinship, with the religion we call Celtic polytheism. Elected Kings led the tribes, and society was divided into three groups: a warrior aristocracy, an intellectual class including druids, poets, and jurists, and everyone else.

Women participated both in warfare and in kingship, and all the offices of high and low kings were filled by election under the system of tanistry, both factors which would confuse Norman writers expecting the feudal principle of primogeniture where the succession goes to the first born son.

Little is known of family structure, but Athenaeus in his Deipnosophists, 13.603, claims that "the Celts, in spite of the fact that their women are very beautiful, prefer boys as sexual partners. There are some of them who will regularly go to bed - on those animal skins of theirs ­ with a pair of lovers," implying with a woman and a boy.

Celtic Societies

Celtic societies were organised around warfare, but this seems to have been more of a sport focussed on raids and hunting rather than organised territorial conquest, drawing obvious comparisons to warfare among Native Americans prior to European contact. This was the age of Hillforts and duns, but there was apparently no urbanization.

Although Celtic gods varied from region to region and tribe to tribe, the Celtic religion had some patterns.

For example like Mediterranean cultures most early Celts worshipped in sacred groves. This was once postulated to have occured because of Celts trading with Mediterranean cultures; however, evidence from Hallstatt era finds show that the earliest Celts practiced this before such trade took place. More reasonably, it is a byproduct of most primitive religion to worship in such a way.

However, La Tene Celts also built temples of varying size and shape, though they still usually maintained sacred trees, or votive pools. Worship was, in this way, defered to temples, when they were available. Numerous temples were converted by the Romans, and with little difficulty; the design was rather similar to Roman temples, as they were both highly influenced by the Greeks, architecturally speaking.

Druids

Their druid postitions vary; a druid is not always a priest. Druids are any members of a Celtic society who had what we would view today as a college education. The most educated druids were usually doctors, priests, and heralds, as these occupations required the most memorization and skill for their practices.

Priests from this class were in charge of a great deal of religious festivals, as well as organizing the calendar; a daunting task as the Celtic calendar is incredibly accurate, but required manual correction about every 40 years, meaning lengthy mathematic discourse.

There are many questions arising as to what calendrical practice was used by the Celtic people. Regarding this issue there are three primary schools of thought. These three theories all attempt to offer us a better understanding of the Celtic calendar. To use the term 'Celtic calendar' is somewhat inaccurate, as it were the Druids who were primarliy concerned with calendar-keeping.

One of the most commonly accepted beliefs holds that the year was divided into thirteen months with an extra day or so the end of the year used to adjust the calendar. This theory states that the months correspond to the vowels of the Ogham or Celtic Tree Alphabet. For every of the months there was a designated tree. From this a 'tree calendar' wheel emerged

Most archaeologist and historians accept another calendar. This calender is represented by the surviving fragments of a great bronze plate, the Coligny Calendar, which originally measured 5 feet by 3-1/2 feet. This plate, found in eastern France, was engraved in the Gaulish language (similar to Welsh) in Roman-style letters and numerals. It depicts a system of time keeping by lunar months, showing 62 consecutive months with 2 extra months inserted to match the solar timetable. They appear to have worked with a 19-year time cycle that equaled 235 lunar months and had an error of only half a day.

The third school of thought is an amalgam of both of the others. The proponents of this last theory believe that the first calendar pre-dates the Coligny discovery.

It is from ancient writers such as Caesar that we learn that the Celts were to have counted by nights and not days and in reckoning birthdays and new moon and new year their unit of reckoning is the night followed by the day.

Ancient Celtic philosophy believed that existence arose from the interplay between darkness and light, night and day, cold and warmth, death and life, and that the passage of years was the alternation of dark periods (winter, beginning November 1) and light periods (summer, starting May 1).

The Druidic view was that the earth was in darkness at its beginning, that night preceded day and winter preceded summer a view in striking accord with the story of creation in Genesis and even with the Big Bang theory. Thus, Nov. 1 was New Year's Day for the Celts, their year being divided into four major cycles. The onset of each cycle was observed with suitable rituals that included feasting and sacrifice. It was called The Festival of Samhain - linked with Halloween.

The Celts measured the Solar year on a wheel, circle or spiral, all of which symbolize creation and the constant movement of the universe ­ growth and development.

To the ancients, the heavens appeared to wheel overhead, turning on an axis which points to the north polar stars. At the crown of the axis, a circle of stars revolved about a fixed point, the Celestial Pole, which was believed to be the location of Heaven.

At the base of the axis was the Omphalos, the circular altar of the Goddess' temple. The universe of stars turning on this axis formed a spiral path, or stairway, on which souls ascended to Heaven.

This Sunwise, clockwise, or deiseal (Gaelic), motion of the spirals represented the Summer Sun. The continuous spirals with seemingly no beginning or end signified that as one cycle ended another began ­ eternal life. The spiral's never-ending, always expanding, motion also symbolized the ever- increasing nature of information and knowledge. Many of these symbols often also appeared in triplicate, a sign of the divine.

In addition, the seasons of the year were thought to be part of this cycle. In Gaelic, the names of the four seasons date back to pre-Christian times:

The social structure of Iron Age Celtic society was highly developed. It was a tribal society that was bonded together by a complex system of laws and social customs. The established body of Law was known as 'Fenechas', the law of the Feine (Freemen), or more commonly, the Brehon Laws. This body served the People for centuries.

The most common body of Brehon Laws was codified in 438, by the order of Laighaire, a High King of Ireland. The proceedings by which this work was done by three Kings, three Brehona (Recitors of the Law), and three Christian missionaries. By this act Pagan Filí and Christian monks came together and worked out a set of laws that was workable for people of both religions. The body of that law has been transmitted to us in the volumes known as the Senchus Mor.

The body of Law known as Brehon Law, as contained in the Senchus Mor is a body of national law. However, national law was secondary to local law. Whether local or national it was the Brehons who acted as the recitors of the Law.

There has been some confusion about who acted as the judge. It was the nobility who acted as such. As stated the Brehons were the recitors of the Law. After the Brehon had recited the Law, only then could the King or Queen render a decision. This is why lore is replete with examples of the Kings or Queens Druid, actually the Ard-Fili, having the right to speak before the King.

If the Brehon, who was a member of the intellectual/skilled caste, recited the law incorrectly they were expected to forfeit their fee and pay damage costs. The Brehon laws were responsible for regulating how people interacted. Hospitality, etiquette and other things were set out in ways that left little room for doubt. The codes of behavior established in the Law was such that all members of a family had to adere to it.

Codes of behavior and levels of responsibility were laid down in the laws for each social group. The more responsibility a social group had, the more restrictions were placed on them. Status was determined by the ownership of cattle and a few other things. There was no concept of land ownership in early Celtic society. This stands in sharp contrast to the Roman and Anglo patterns.

Druids also carried out sacrifices of crops, animals, and during specific festivals, humans. In a Celtic society, people were not executed for crimes, except during these festivals. Such executions varied, depending on what god the execution was dedicated to. Among the most famous is the human sacrifices practiced in the course of Essus worship.

Essus Worship

Essus was, more or less, a benevolent law god to many Celts, particularly Gauls. However, Essus worship also intoned a sense of merciless behavior toward repeated criminals, rapists, traitors, and other societal dregs. The offender, if found guilty, would be taken to the temple of Essus, where an oak would be growing through an opening in the temple roof. His stomach would be cut open, and he would be hung from an oak branch.

Other Gods

The Celts' gods were often named after natural things. For example the source of rivers would often have their own goddesses, though rarely many gods. Another theme with Celt gods were triple deities; not only goddesses, but numerous gods. For example the Mothers of Britain, or Cromm Cruach's slovenly, deific, and humanistic forms. The main deities of Celtic religion, contrary to much misconception, were usually male.

The world in some remaining myths is often depicted as having been forged by a god with a hammer, such as Dagda or Sucellos, who then poured all life from a magic cauldron or cup; a source of pre-Christian Holy Grail' myths in Celtic societies.

While deities varied, several constant deities or demigods existed over a wide area. A great example is Lugos, a heroic sun god from Gaul and the southern, Gallic parts of Britain. He is also known as Lugh (in Ireland), Llew (in non-Gallic Britain), and Lug (among Celtiberians, who were not culturally true Celts). Early depictions of him exist as early as the Hallstatt era, suggesting him as one of the longest existing gods of Celtic religion.

Similar is the horse and fertility goddess, Epona, who was also worshipped by the Romans when they came to rule Gaul. She also seems to have existed from the early era. Finally, there is Sucellos, who is argued by some to have been the 'creator of the universe' in some Celtic religions. He is party to Dagda of Ireland, and was worshipped over an enormous area, including by non-Celtic peoples such as the Lusitani.

He was the patron god of the Ordovices tribe of Britain, and was built up by the Arverni and their allies to replace the druidic god Cernunnos, as the Gallic druids were allies of their enemies in the rule for Gaul; the Aedui.Other religious practices also existed; Celts seem to have universally removed body hair.

Some postulate this as religious, but was more realistically part of the Celtic propensity for cleanliness. Body hair kept dirt close to the body, and Celts were an extremely cleanly people, so this was unacceptable. However, Celts also took heads from dead enemies. This was definitely a religious practice in origin.

However, even post-Christian Gaels continued this practice into the middle ages; some Irish even took to scalping the heads that they took, so they could braid the scalp through rings on their weapons. The religious connotations by that point were slim, but it does imply that taking heads had incredible cultural importance to have persisted so long after the religious background had been removed.

Souls

To our understanding, Celts believed the soul resided in the head, and that capturing a head meant that one captured the soul of an opponent, and that when a Celt died, the dead whom he had collected would serve him as slaves for eternity.

"Amongst the Celts the human head was venerated above all else, since the head was to the Celt the soul, centre of the emotions as well as of life itself, a symbol of divinity and of the powers of the other-world." - Paul Jacobsthal, Early Celtic Art.

The Celtic cult of the severed head is documented not only in the many sculptured representations of severed heads in La Tene carvings, but in the surviving Celtic mythology, which is full of stories of the severed heads of heroes and the saints who carry their decapitated heads, right down to Sir Gawain and the Green Knight who picks up his own severed head after Gawain has struck it off, just as St. Denis carried his head to the top of Montmartre. Separated from the mundane body, although still alive, the animated head acquires the ability to see into the mythic realm.

Diodorus Siculus, in his 1st century History had this to say about Celtic head-hunting: "They cut off the heads of enemies slain in battle and attach them to the necks of their horses. The blood-stained spoils they hand over to their attendants and carry off as booty, while striking up a paean and singing a song of victory; and they nail up these first fruits upon their houses, just as do those who lay low wild animals in certain kinds of hunting.

They embalm in cedar oil the heads of the most distinguished enemies, and preserve them carefully in a chest, and display them with pride to strangers, saying that for this head one of their ancestors, or his father, or the man himself, refused the offer of a large sum of money. They say that some of them boast that they refused the weight of the head in gold; thus displaying what is only a barbarous kind of magnanimity, for it is not a sign of nobility to refrain from selling the proofs of one's valour. It is rather true that it is bestial to continue one's hostility against a slain fellow man."

The Celts also believed that if they attached the head of their enemy to a pole or a fence near their house, the head would start crying when the enemy was near.

The Celtic headhunters venerated the image of the severed head as a continuing source of spiritual power. If the head is the seat of the soul, possessing the severed head of an enemy, honorably reaped in battle, added prestige to any warrior's reputation. According to tradition the buried head of a god or hero named Bran the Blessed protected Britain from invasion across the English Channel.

Celtic mythology is the mythology of Celtic polytheism, the apparent religion of the Iron Age Celts. Like other Iron Age Europeans, the early Celts maintained a polytheistic mythology and religious structure. Among Celtic peoples in close contact with Rome, such as the Gauls and Celtiberians, their mythology did not survive the Roman empire, their subsequent conversion to Christianity, and the loss of their Celtic languages.

Ironically it is through contemporary Roman and Christian sources that what we do know of their beliefs has come down to us. In contrast, those Celtic peoples who maintained either their political or linguistic identities (such as the Gaels and Brythonic tribes of the British Isles) did transmit at least vestigial remnants of the mythologies of their Iron Age forebears, which were often recorded in written form during the Middle Ages.

Because of the scarcity of surviving materials bearing written Gaulish, it is surmised that the pagan Celts were not widely literate - although a written form of Gaulish using the Greek, Latin and North Italic alphabets were used (as evidenced by votive items bearing inscriptions in Gaulish and the Coligny Calendar). Caesar attests to the literacy of the Gauls, but also wrote that their priests, the druids, were forbidden to use writing to record certain verses of religious significance (Caesar, De Bello Gallico 6.14) while also noting that the Helvetii had a written census (Caesar, De Bello Gallico 1.29).

Rome introduced a more widespread habit of public inscriptions, and broke the power of the druids in the areas it conquered; in fact, most inscriptions to deities discovered in Gaul (modern France), Britain and other formerly (or presently) Celtic-speaking areas post-date the Roman conquest.

And although early Gaels in Ireland and parts of modern Wales used the Ogham script to record short inscriptions (largely personal names), more sophisticated literacy was not introduced to Celtic areas not conquered by Rome until the advent of Christianity; indeed, many Gaelic myths were first recorded by Christian monks, albeit without most of their original religious meanings.

The classic entry about the Celtic gods of Gaul is the section in Julius Caesar's Commentarii de bello Gallico (52­51 BC; The Gallic War). In this he names the five principal gods worshipped in Gaul (according to the practice of his time, he gives the names of the closest equivalent Roman gods) and describes their roles. Mercury was the most venerated of all the deities and numerous representations of him were to be discovered. Mercury was seen as the originator of all the arts (and is often taken to refer to Lugus for this reason), the supporter of adventurers and of traders, and the mightiest power concerning trade and profit. Next the Gauls revered Apollo, Mars, Jupiter, and Minerva. Among these divinities the Celts are described as holding roughly equal views as did other populations: Apollo dispels sickness, Minerva encourages skills, Jupiter is in charge of the skies, and Mars influences warfare. In addition to these five, he mentions that the Gauls traced their ancestry to Dis Pater.

As typical of himself as a Roman of the day, though, Caesar does not write of these gods by their Celtic names but by the names of the Roman gods with which he equated them, a process that significantly confuses the chore of identifying these Gaulish gods with their native names in the insular mythologies. He also portrays a tidy schema which equates deity and role in a manner that is quite unfamiliar to the colloquial literature handed down. Still, despite the restrictions, his short list is a helpful and fundamentally precise observation. In balancing his description with the oral tradition, or even with the Gaulish iconography, one is apt to recollect the distinct milieus and roles of these gods.

Caesar's remarks and the iconography allude to rather dissimilar phases in the history of Gaulish religion. The iconography of Roman times is part of a setting of great social and political developments, and the religion it depicts may actually have been less obviously ordered than that upheld by the druids (the priestly order) in the era of Gaulish autonomy from Rome. Conversely, the want of order is often more ostensible than factual. It has, for example, been noticed that out of the several hundred names including a Celtic aspect testified in Gaul the greater part crop up only once.

This has led some scholars to conclude that the Celtic deities and the related cults were local and tribal as opposed to Pan-Celtic. Proponents of this opinion quote Lucan's reference to a divinity called Teutates, which they translate as 'tribal spiri't (*teuta is believed to have meant 'tribe' in Proto-Celtic). The apparent array of divine names may, nonetheless, be justified differently: many may be mere labels applied to key gods worshiped in extensive Pan-Celtic cults. The concept of the Celtic pantheon as a large number of local deities is gainsaid by the numerous well-testified gods whose cults seem to have been followed across the Celtic world.

Though the Celtic world at its greatest extent covered much of western and central Europe, it was not politically unified nor was there any substantial central source of cultural influence or homogeneity; as a result, there was a great deal of variation in local practices of Celtic religion (although certain motifs - for example, the god Lugh - appear to have diffused throughout the Celtic world). Inscriptions to more than three hundred deities, often equated with their Roman counterparts, have survived, but most appear to have been genii locorum, local or tribal gods, and few were widely worshipped.

The nature and functions of these ancient gods can be deduced from their names, the location of their inscriptions, their iconography, the Roman gods they are equated with, and similar figures from later bodies of Celtic mythology.

The oldest body of myths is found in early medieval manuscripts from Ireland. These were written by Christians, so the formerly divine nature of the characters is obscured. The basic myth appears to be a war between two apparently divine races, the Tuatha Dé Danann and the Fomorians, which forms the basis for the text Cath Maige Tuireadh (the Battle of Mag Tuireadh), as well as portions of the great pseudohistorical construct Lebor Gabála Erenn (the Book of Invasions). The Tuatha De represent the functions of human society such as kingship, crafts and war, while the Fomorians represent chaos and wild nature.

The gods of Britain, also obscured by centuries of Christianity, have come down to us in manuscripts from Wales. Here the two main groups of former gods are the children of Dôn and the Children of Llyr, although any distinction of function between the two groups is not apparent.

References:

Wikipedia

Online

Collis, John. The Celts - Origins, Myths & Inventions. Stroud: Tempus Publishing, 2003. ISBN 0752429132.

Cunliffe, Barry. The Ancient Celts. Oxford: Oxford University Press, 1997. ISBN 0198150105.