The first literary reference to the Celtic people, as keltoi or hidden people, is by the Greek Hecataeus in 517 BC.
"Celt" is pronounced /kelt/, and "celtic" as /keltIk/ (in SAMPA). The pronunciation /seltIk/ should only be used for certain sports teams (eg. the NBA team, Boston Celtics, and the SFA side, Celtic FC).
The term 'Celt' or 'Celtic' can be used in several senses - it can denote a group of peoples speaking or descended from speakers of the Celtic Language; or the people of prehistoric Europe who share common cultural traits which are thought to have originated in the Hallstatt and La Tene Cultures. In contemporary terms 'Celtic nations' are usually defined as Wales, Ireland, Scotland, Cornwall, Isle of Man and Brittany due to Celtic languages unique to these areas. Other areas of Europe are associated with being Celtic, such as Galicia in Spain, and Devon, Cumbria and Northumbria in England. Modern day DNA research (such as that by UCL) indicate that the current population of England is primarilly descended from Celtic/ancient British ancestry, although England lacks a surviving common Celtic language. Similarly in Scotland, the Gaelic language is restricted mostly to the northern and western fringes.
The Origins and Geographical Distribution of the Celts
The Urnfield people were the largest population grouping in late Bronze Age Europe and were preeminent from c. 1200 BC until the emergence of the Celts in c. 600 BC. The period of the Urnfield people saw a dramatic increase in population probably due to innovations in technology and agricultural practices. The spread of iron-working led to the development of the Hallstatt culture (c. 700 to 500 BC). The Hallstatt culture effectively held a frontier against incursions from the east by Thracian and Scythian tribes.
The subject of the replacement of the Hallstatt culture ("hall" is the old word for salt) by the La Tène culture, the final stage of the Iron Age, and its gradual transformation into a culture generally referred to as Celtic, is both complex and diverse, however the technologies, decorative practices and metal-working styles of the La Tène were to be very influential on the Celts. The La Tène style was highly derivative from the Greek, Etruscan and Scythian decorative styles with whom the La Tène settlers frequently traded.
Their original homeland has been shown by archaeological findings to have been around the upper reaches of the Danube, in Switzerland, Austria (around the village of Hallstatt) and southern Germany, and before that perhaps the central Asian steppes. From central Europe they spread as far south as the Iberian peninsula, as far north as Scotland and Denmark, as far west as Ireland and as far east as Anatolia, in many cases assimilating the previous inhabitants of these regions as they went.
It was not the Celts but these previous inhabitants who built Stonehenge and the other Neolithic and Bronze Age megalithic monuments in Europe. But even though the Celts did not construct these monuments, the religious significance of these places may well have endured among the conquered people and the Celts eventually adopted the practice of worshipping there as well. Many Celts settled in present-day France. These were the Gauls who are described by Julius Caesar in his Gallic Wars.
Other Celtic tribes invaded Italy, establishing there a city they called Mediolanum (modern Milan) and sacking Rome itself in 390 B.C. Not until 192 B.C. did the Roman armies conquer the last remaining independent Celtic kingdoms in Italy.
Other Central European tribes moved eastwards and settled in Asia Minor, there to become the Galatians (that is, Gauls) to whom an epistle of St Paul's is addressed.
New Theories of Celtic Origins in Britain
There are diverse opinions about the origins of the Celts, some supported by recent DNA studies. In the 1970's Colin Burgess in his book the Age of Stonehenge theorized that Celtic culture in Britain 'emerged' rather that resulted from invasion and that the Celts were not invading aliens but the descendants of the people of Stonehenge. Support for this idea comes from the study by Cristian Capelli, David Goldstein and others at University College, London which shows that genes typical of Ireland are common in mainland Britain and these genes are similar to the genes of the Basque people, who speak a non-Indo-European language. This similarity, they argue, shows that the non-Indo-European native inhabitants of Britain were not wiped out by invasions of either Indo-Europeans bringing farming or Celts in 600BC. They suggest that 'Celtic' culture and the Celtic language were imported to Britain by cultural contact not mass invasion. The genetic similarity is less marked in women in Britain who have a genetic makeup closer to that of Northern Europe possibly because women tended to move to their husbands' homes.
Celts conquered by the Romans
Although they were for a long time the dominant people in central and western Europe, the Celts in France, Britain and Spain were eventually conquered by the Romans. Roman local government closely mirrored pre-Roman 'tribal' boundaries and archaeological finds suggest native involvement in local government. During the Roman era the Celts adopted Christianity and Latin as the official language.
Celts pushed west by Germanic Migration
Elsewhere they were pushed further westwards by successive waves of Germanic invaders, who had themselves been evicted from the Indo-European homeland on the Southern Russian steppes by Mongols, Huns and Scythians. 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 the Spanish province of Galicia (i.e., Gaul), 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 Britain. 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 clearly an adaptation of a much older Irish legend about the exploits of the hero Cu Chulainn.
Argument rages in the academic world as to whether the Celts in Britain were mostly wiped out/pushed west as the lack of evidence for influence of the Celts on Anglo-Saxon society suggests, or whether the Anglo-Saxon 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. Recent DNA studies have supported that Anglo-Saxon England evolved from the imposition of a new culture on the previously Celtic people of England.
Celtic Social System and Arts
The pre-Christian Celts had a well-organised social hierarchy. They produced little in the way of literary output, preferring the bardic, oral, tradition. They were highly skilled in visual arts and produced a great deal of intricate and beautiful metalwork.
Celts as head-hunters
"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 of 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 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.
Celt - a contested term?
The use of the word 'Celtic' as a valid umbrella term for the pre-Roman peoples of Britain has been challenged by a number of writers - including Simon James of the British Museum. His book The Atlantic Celts - Ancient People Or Modern Invention? makes the point that the Romans never used the term 'Celtic' in reference to the peoples of the Atlantic archipelago, i.e the British Isles. He makes it clear that the term was coined as a useful umbrella term in the 18th Century when the English Kingdom united with the Scottish. The British found it expedient to use the hitherto neutral term British for their own imperial ends. Thus a new term was needed to unite nationalists in Scotland, Ireland and Wales. The term 'Celtic' fit the bill. James makes the point that archaeology does not suggest a united Celtic culture and that the term is misleading, no more meaningful that 'Western European' would be today, and is also anachronistic.
Names for Celts
The origin of the various names used since classical times for the people known today as the Celts is obscure and has been controversial. It appears that none of the terms recorded were ever used by Celtic speakers of themselves. In particular, there is no record of the term "Celt" being used in connection with the inhabitants of the British Isles or Ireland prior to the 19 th century.
The name "Gauls"
English Gaul(s), French Gaul(es), Latin Gallus or Galli might be from an originally Celtic ethnic or tribal name (perhaps borrowed into Latin during early, 400 BCE, Celtic expansions into Italy). Its root may be the Common Celtic *galno-power or strength. Greek Galatai seems to be based on the same root, and may have been a loan from Latin, or some other Italic dialect, if it wasn't itself borrowed directly from the same hypothetical Celtic source which gave us Galli (the suffix -atai is simply an ethnic name indicator).
The word "Welsh"
English Welsh, French Gallois ("Welsh"), etc. are Germanic words, yet they ultimately have a Celtic source. They are the result of an early borrowing (in the fourth century BCE) of the Celtic tribal name Uolcae ("Falcons" in Gaulish) into Primitive Germanic (becoming the Primitive Germanic *Walh-, "Foreigner" and the suffixed form *Walhisk-). The Uolcae were one of the Celtic peoples that barred, for two centuries, the southward expansion of the German tribes in central Germany on the line of the Hartz mountains and into Saxony and Silesia.
In the middle ages certain districts of what is now Germany were known as "Welschland" as opposed to "Teutschland".
The name "Celts"
English Celt(s), Latin Celtus or Celti (Celtae), Greek Keltos or Keltoi seem to be based on a native Celtic ethnic name (singular *Celtos or *Celta with plurals *Celtoi or *Celta:s), of unsure etymology. The root would seem to be a Primitive Indo-European *kel- or (s)kel-, but there are several such roots of various meanings to choose from (*kel- "to be prominent", *kel- "to drive or set in motion", *kel- "to strike or cut" etc.)