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Let me begin with a caveat:
“Celtic culture” is a real thistle of a thing to define.
As I explored in my previous post, “Who Were the Ancient Celts?”, the Celts were not a continuous lineage of people.
In its scholarly application, “Celtic” refers—first and foremost—to a language group.
Over the centuries, different Celtic-speaking tribes (the primary ones being the Boii, the Britons, the Celtiberians, the Gaels, the Galatians, Gallaeci, the Gauls, and the Lepontii) would come to occupy vastly different geographies across Europe (and Asia Minor) and, naturally, their customs would be influenced by different neighboring cultures.
But to be sure, there were commonalities to be found amongst these Celtic tribes beyond language.
What Is Celtic Culture?
If I were forced, at spear-point, to provide a succinct definition of Celtic culture, I would write the following:
Celtic culture refers to the arts, customary beliefs, and social institutions shared by Celtic-speaking peoples.
Decorative metal torcs, for example, were a staple of Celtic jewelry-making across ancient Europe—“from Iberia to Bohemia,” according to the World History Encyclopedia.
Torcs designed in La Tène style—a highly ornamental Celtic style named for an archaeological site in Switzerland—have also been discovered at sites in Britain and Ireland, again suggesting some cultural connective tissue amongst the tribes.
There’s also the broader field of Celtic art to consider.
While many of us, when thinking of “Celtic art,” may conjure up images of ringed crosses or elaborate, snaking Celtic knots drawn in the corners of illuminated manuscripts, the reality is those examples are primarily Irish or, more broadly, Gaelic/Goidelic.
And yet…there is something Celtic about those knots and crosses.


Indeed, artwork found across the Celtic world shows a shared preference for circular forms and spirals, including triskelions or triskeles (triple spirals). And, more generally, geometrical decorations were preferred to figurative subjects (i.e., subjects you can see in the real-world).
Then, of course, there’s Celtic paganism (a.k.a. the ancient Celtic religion) and its associated mythology. While originating in Continental Europe, this belief system/storytelling tradition shares several similarities with ancient Irish and Welsh belief systems/storytelling traditions.
Here’s an example. (And yes, long-time IrishMyths.com readers, I’m definitely about to name-drop everyone’s favorite multi-talented sun-god…)
The Irish god Lugh and his Welsh cognate Lleu (also: Llew) are both incarnations of an earlier continental Celtic god, Lugus (also: Lugos).

Spoiler alert for the Mythological Cycle of Irish mythology: Lugh, the Irish sun-god and “god of many talents,” is a super-important figure who saves Ireland by killing his own grandfather, Balor of the Evil Eye, during the Second Battle of Mag Tuired.
Mythological escapades aside, Lugh was also clearly a significant religious figure to the ancient Irish, as he lent his name to their August 1st feast day of Lughnasa—one of four major holidays on the Irish pagan calendar (the others being Samhain, Imbolc, and Beltane).
So, was Lugh’s continental equivalent, Lugus, similarly important to the religion of the ancient Celts?
We can only speculate.
Oh, and we can also look at this list of places that were named in the god’s honor:
- Lyon—formerly Lugdunum, meaning “Fortress of Lugus” (France)
- Léon (France)
- Loudan (France)
- Laudun-l’Ardoise (France)
- Laon (France)
- Leiden (Holland)
- Liegnitz (Silesia—modern-day Poland)
- Lugones (Asturias, Spain)
I should also mention that Dinlleu in Wales; Loudoun and Lothian in Scotland; and Luton and Carlisle (formerly Luguvalum) in England are all also thought to be named for Lugus (or his cognates). Ditto London (formerly Londinium), which, like Lyon, some scholars argue was originally named “Lugdunum” or something similar. (Granted, that’s a controversial and still largely unproven hypothesis.)
But it wasn’t just the gods who permeated the religious lives of different Celtic peoples.
Druids—a class of intellectual priest-judges who, in some cases, wielded more power than the chieftains they served—were also a common fixture in Celtic-speaking societies across Europe.
The astronomical knowledge of these ancient Celtic druids is still on display in the form of calendars, none so famous as the Coligny calendar (discovered in what is now Coligny, France).
While fragmented, reconstruction of the first-century BCE bronze tablet calendar reveals a sophisticated lunisolar calendrical system that attempts to synchronize the lunar month with the solar year. (It did this by having weeks that were five days long, months that were six of those weeks long, years that were twelve of those months long, and five-year cycles that amounted to sixty regular months plus two “intercalary” months. But I digress.)

So there, at a glance, is Celtic culture (or at least a simplistic interpretation of it).
Now, let’s gone on with the task at hand:
Figuring out where the heck this culture came from geographically.
The Geography of the Ancient Celts
According to British historian Peter Berresford Ellis, the Celts were “the first transalpine people to emerge into recorded history,” (source: A Dictionary of Irish Mythology, 1987).
A quick “transalpine” explainer:
For centuries, the Alps—Europe’s tallest and most extensive mountain range—deterred contact between the Greco-Roman world of Mediterranean Europe and the Celtic world of Central and Northwestern Europe.
It was sort of like a natural Game of Thrones ice-wall separating the “civilized” Greeks and Romans from the Celtic “wildlings.” (Or at least that’s what some Classical writers would have us believe.)
But as history has shown us time and time again (re: Hannibal, Napoleon), while the Alps are notoriously treacherous, they are not impassable.
To quote Ellis:
“By the ninth century BC the Celts had settled extensively in southern France; they moved into the Iberian peninsula and by the sixth century crossed the Alps into the Italian peninsula.”
source: A Dictionary of Irish Mythology (1987)
Ellis goes on to explain that the “greatest expansion” of the Celts occurred in the third century BCE, a period that saw Celtic tribes branching out as far as Asia Minor/Anatolia/Turkey (to the east) and Ireland (to the west).

Granted, the precise time period when Celtic peoples arrived in Ireland and Britain is still up for debate—and that’s a beefy enough topic to deserve its own article in the near future.
Regardless of when they arrived, it is here, and only here—in Ireland, Britain, and a few other places on the fringes of Atlantic Europe—where Celtic culture endures.
But where (and when) did Celtic culture begin?
To answer that, we’ll need to trace the evolution of the Celtic language.
The Philology (Linguistic History) of the Celts
The six (sometimes seven, or even eight) so-called modern “Celtic nations”—Ireland, Scotland, the Isle of Man, Wales, Cornwall, and Brittany (and sometimes Galicia and Asturias)—represent the few regions where Celtic languages/cultural traditions continue on in some form or another.
Specifically, Gaelic/Goidelic languages continue to be spoken in Ireland, Scotland, and the Isle of Man, and Brittonic/Brythonic languages continue to be spoken in Wales, Cornwall, and Brittany.
These languages, known collectively as the Insular Celtic languages, are the only Celtic languages still in existence.
The Continental Celtic languages—Gaulish included—have all gone extinct. (And yes, even though Brittany is part of continental Europe, Breton is technically a Brittonic—and thus, Insular Celtic—language.)
Despite extinction, however, the influence of the Continental Celtic languages can still be felt. Case in point:
Philology—the study of the history of language—reveals that modern French borrowed hundreds of words from the now-extinct Gaulish language.
And these aren’t obscure Scrabble words, mind you.
Common French words including cabane (cabin), cloche (bell), and cheval (horse)—to name just a few—all have Gaulish (Celtic) roots.
What makes this exercise more interesting is when we translate these same common words—cabin, bell, and horse—into modern Irish (a Gaelic/Goidelic Celtic language) and Welsh (a Brittonic/Brythonic Celtic language). In Irish, we get cábáin, clog, and capall, while in Welsh we get caban, cloch, and ceffyl.
Even to a non-linguist, the similarities are easy enough to see.
English | cabin | bell | horse |
French (Gaulish root) | cabane | cloche | cheval |
Irish | cábáin | clog | capall |
Welsh | caban | cloch | ceffyl |
And if you think this is all a load of crap, I give you…”crap.”
That’ve been “*kakkā” in Proto-Celtic (more on that soon).
In French, it’s “caca.”
In Irish, it’s “cac” (shit) or “cacamas” (crap).
In Welsh, it’s “cachu” (shit).
However, and this is a pretty big however, not all scholars agree with the Continental/Insular approach to Celtic language classification; some distinguish between “P-Celtic” and “Q-Celtic” languages instead.
The short version:
P-Celtic speakers include(d) the Gauls and the Britons, who favor(ed) using the “p” consonant sound in certain words, whereas “Q-Celtic” speakers include(d) the Celtiberians and the Gaels, who retain(ed) the “q” (kw) sound from the earlier Proto-Celtic, from which P- and Q-Celtic were both descended.
(Side note: can you believe I haven’t made a “mind your Ps and Qs” joke yet? Be grateful.)
For an example of this linguistic phenomenon, I give you the number four:

What’s especially interesting here is that genetic studies have revealed an ancestral link between modern Irish people and the people of Galicia, lending credence both to the P/Q Celtic language classification system (which groups the Gaels and Celtiberians together) and to the Milesian invasion story from Irish myth, which proclaims that the last people to settle in Ireland came from Spain.
And yet…
Most scholars agree that the Celtiberian and Gaelic languages developed separately, i.e., each was an independent offshoot of an earlier Proto-Celtic language.
Worth noting: the P/Q interpretation of the Celtic language tree includes an intermediary step—a Gallo-Brittonic language—between Proto-Celtic and the later Gaulish and Brittonic languages.
In contrast, the Continental/Insular interpretation adds an intermediary step—a common Insular Celtic language—between Proto-Celtic and the later Gaelic and Brittonic languages.

But regardless of which (if either) of these “forks” in the Celtic language occurred, all roads lead back to the same place…
Proto-Celtic: The Precursor to All Celtic Languages
Proto-Celtic (a.k.a. Common Celtic) is the parent language of all known Celtic languages, be them Continental or Insular or P-Celtic or Q-Celtic.
An offshoot of Proto-Indo-European, Proto-Celtic is theorized to have been spoken between 1300 and 800 BCE, though some scholars peg it more precisely to the late Late Bronze Age (1200 to 900 BCE).
Now, traditional wisdom tells us that the Proto-Celtic language originated with the Urnfield culture of Central Europe.
The Urnfield peoples—so-named for their mortuary practice of cremating the dead, putting the ashes in urns, and burying the urns in fields—occupied territories from Hungary to France, and north to the North Sea and south to the Alps. But it is in modern-day Hungary specifically where the Urnfield culture is believed to have been born.
During the Iron Age, the Urnfield culture was succeeded by the Hallstatt culture—named for archaeological sites found in Hallstatt, Austria—and later the Hallstatt culture was succeeded by the aforementioned La Tène culture of Switzerland.
And so, the traditional Urnfield-Hallstatt theory of the origins of Celtic culture (also known as the “Celtic from the East theory”) posits that the Proto-Celtic language spread—through migration, or cultural diffusion, or both—from Central Europe into Gaul, Iberia, Italy, Britain, Ireland, and so on.
Here’s my favorite bit of evidence that supports this east-to-west origin story:
In Irish mythology, the pantheon of Irish gods is called the Tuatha Dé Danann, a name that translates to “peoples of the goddess Danu” or “tribe of the goddess Danu.” Danu (also: Dana, Anu) is a Celtic mother goddess, and it’s likely she is the namesake of the Danube River (or vice versa).
The second-longest river in Europe, the Danube originates in Germany and flows for 1,770 miles (2,850 kilometers) through (or past) Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova, and Ukraine.
So, we can put a bow on this one, right? We cracked it:
Celtic culture originated in what is now Hungary before spreading west into Austria, Switzerland, and beyond.
Only, here’s the thing:
Not everyone believes that Celtic origin story.
The “Celtic from the West” Theory
Not to blame the dead, but speakers of ancient Celtic languages did not do a great job of leaving behind primary source materials.
Want to study some old Proto-Celtic inscriptions? Unfortunately, no examples of the language in written form survived into modernity—a fact that left the door open for scholars to come up with plausible alternatives to the prevailing “Celtic from the East” hypothesis.
Allow me to elaborate…
The oldest example of the written Celtic word dates back to the 6th century BCE. It was written in Lepontic, an offshoot of Gaulish, and was discovered in northern Italy.

The second-oldest example of the written Celtic word, meanwhile, dates back to the 2nd century BCE. It was written in Celtiberian and, naturally, was discovered in Iberia.

Then there are those Celtic place names to consider (remember all those towns named after the Celtic god Lugh?), which are concentrated in Northwestern Europe—Atlantic Europe especially.
British archaeologist Barry Cunliffe and American linguist and historian John T. Koch took all of this into consideration when they proposed an Atlantic coastal origin for the Proto-Celtic language.
This “Celtic from the West” theory posits that instead of moving west with the Urnfield, Hallstatt, and La Tène cultures, the Proto-Celtic language moved east with the Bell Beaker culture of the Early Bronze Age (800 to 1800 BCE). That would date the birth of the Proto-Celtic language to approximately 3000 BCE (according to Cunliffe), which is much earlier than previously thought.
However, it should be noted that linguists reject some of this theory’s key assumptions—particularly the assumption that the Tartessian language, found in Iberian inscriptions from the 7th century BCE, was actually Celtic in origin. (Most linguists consider Tartessian unclassifiable, i.e. there isn’t enough evidence to convincingly place it in any existing language family.)
But what if I told you there was another theory of the origins of Celtic culture; a theory that didn’t require such bold assumptions; a theory that, actually, come to think of it, is really rather elegant…
The “Celtic from the Center” Theory
What region immediately comes to mind when thinking of the ancient Celts?
For me, it’s Gaul.
Just so we’re all on the same page here, a quick definition:
Gaul is the ancient territory that is roughly the geographic equivalent of modern France but which also includes parts of Switzerland, Belgium, the Netherlands, Luxembourg, Germany, Austria, and the Czech Republic. It was the ancestral home of the Gaulish-speaking Celtic tribes, who emerged there in the 5th-century BCE bearing La Tène culture.
La Tène culture represents (arguably) the pinnacle of Celtic artistry. It is La Tène material culture in particular that spreads to the rest of the Celtic world, including Britain and Ireland, where it influences the creation of “Celtic” knots and ringed crosses and swirling triskeles.

And where did La Tène culture develop?
Gaul.
This is the region where “Celtic,” both as a material culture and as a classification for a group of people, really comes into its own. Indeed, for many Classical writers, the terms “Gauls” and “Celts” were synonyms.
And don’t forget about the oldest-known example of the Celtic language, which was found in Northern Italy (just a hop-skip-and-a-jump-over-the-Alps away for the Gauls) and was written in Leptonic, an offshoot of Gaulish.
Then there’s that second inscription, found in Iberia, Gaul’s slightly-more-accessible neighbor (not that crossing the Pyrenees is a walk in the park).
All this to say…
It sure seems plausible that Celtic culture actually started in Gaul and then spread outward in all directions.
And that’s essentially Celticist Patrick Sims-Williams’ “Celtic from the Center” theory:
“Celtic presumably emerged as a distinct Indo-European dialect around the second millennium BC, probably somewhere in Gaul (Gallia/Keltikê), whence it spread in various directions and at various speeds in the first millennium bc, gradually supplanting other languages…”
source: “An Alternative to ‘Celtic from the East’ and ‘Celtic from the West’”, Cambridge Archaeological Journal, Volume 30, Issue 3, 02 April 2020
The two main arguments Sims-Williams gives in support of his “Celtic from the Center” theory:
- As I already mentioned, Gaul is relatively close to Italy, which, according to Sims-Williams, “suits the view that Italic and Celtic were in some way linked in the second millennium [BCE].”
- Gaul’s very centrality explains how the Celtic language was able to spread east and west, north and south, while avoiding “major dialectal splits.”
Think about it:
If Proto-Celtic had really originated in Hungary as early as 1300 BCE, or in Atlantic Europe as early as 3000 BCE, what are the odds such a language would’ve remained relatively intact hundreds (if not thousands) of years later after traveling hundreds (if not thousands) of miles to the west or east?
Having a centrally located point of origin makes the Celtic expansion more plausible.
Final Thought: Were the Celts the Ultimate Assimilators?
To reiterate a point I’ve hopefully already made abundantly clear, Celtic culture was—first and foremost—a culture of shared language. If that makes sense. Does that make sense? (Look, this little article of mine is already way too long as it is. You get what I’m saying.)
And while I did my best to incorporate in this article the common material aspects of Celtic culture, the reality is the Celts didn’t leave behind a whole lot for us to look at.
One reason for that may be that the ancient Celtic-speaking peoples were exceptional assimilators.
To quote Sims-Williams puts:
“The Celts, who took their language with them, may often have adopted the material culture of the territories where they settled, thereby becoming archaeologically indistinguishable.”
It’s a potentially interesting example of how a people’s language can persist even when all of the superficial elements of said people’s culture have been abandoned.
And how fortunate we are that the Celtic languages did persist. Because if they hadn’t, humanity would have been robbed of one of the world’s greatest storytelling traditions.
Without Celtic languages, there would be no Welsh mythology; there would be no Irish mythology.
And perhaps most egregiously of all, I would be out of a job.
Further Reading:
The Ancient Celts by Barry Cunliffe
A Brief History of the Celts by Peter Berresford Ellis
The Celts: Search for a Civilization by Alice Roberts
The Historical Atlas of the Celtic World by Dr. Ian Barnes
Celts: The History and Legacy of One of the Oldest Cultures in Europe by Martin J. Dougherty
The Celtic World by Miranda J. Green
The Celts: The People Who Came Out of the Darkness by Gerhard Herm
The Celts: Uncovering the Mythic and Historic Origins of Western Culture by Jean Markale
P.S. Interested in Celtic culture? Check out…
Samhain in Your Pocket (Celtic Pocket Guides 2)
Perhaps the most important holiday on the ancient Celtic calendar, Samhain marks the end of summer and the beginning of a new pastoral year. It is a liminal time—a time when the forces of light and darkness, warmth and cold, growth and blight, are in conflict. A time when the barrier between the land of the living and the land of the dead is at its thinnest. A time when all manner of spirits and demons are wont to cross over from the Celtic Otherworld. Learn more…
Neon Druid: An Anthology of Urban Celtic Fantasy
“A thrilling romp through pubs, mythology, and alleyways. NEON DRUID is such a fun, pulpy anthology of stories that embody Celtic fantasy and myth,” (Pyles of Books). Cross over into a world where the mischievous gods, goddesses, monsters, and heroes of Celtic mythology live among us, intermingling with unsuspecting mortals and stirring up mayhem in cities and towns on both sides of the Atlantic, from Limerick and Edinburgh to Montreal and Boston. Learn more…
More the listenin’ type?
I recommend the audiobook Celtic Mythology: Tales of Gods, Goddesses, and Heroes by Philip Freeman (narrated by Gerard Doyle). Use my link to get 3 free months of Audible Premium Plus and you can listen to the full 7.5-hour audiobook for free.