To modern ears, the word “Celtic” evokes traditional art, literature and music from Ireland and Scotland. But the ancient Celts were a widespread group of people with origins in central Europe. See what historians have learned about this rich and complex collection of tribes.

1. The Celts were the largest group in ancient Europe.

The ancient culture known as the Celts once extended far beyond the British Isles. With territory stretching from Spain to the Black Sea, the Celts were geographically the largest group of people to inhabit ancient Europe.

The difficulty of tracing Celtic history is that none of these ancient peoples living in Western or Central Europe would have called themselves Celts. That name came from the Greeks, who made their first contact with a “barbarian” people they called the Keltoi in 540 B.C. on the southern coast of France. The ancient Celts were never a single kingdom or an empire, but a collection of hundreds of tribal chiefdoms with a shared culture and distinctive language.

2. The Celts were described as barbaric warriors.

Since the Celts themselves left no written histories, we’re left to rely on the admittedly biased accounts of their enemies in battle, the Greeks and later the Romans. Historians don’t know why the Greeks called them the Keltoi, but the name stuck, and the Celts developed a reputation in Greece as hard-drinking, hard-fighting savages. Celtic warriors often battled naked and were prized as mercenaries throughout the Mediterranean.

The Romans called the Celts Galli or Gallia and frequently clashed with Celtic tribes that invaded Roman outposts in Northern Italy. In 387 B.C, a fearless Celtic warlord named Brennus sealed the barbaric reputation of the Celts by violently sacking and pillaging Rome and putting most of the Roman Senate to the sword.

Centuries later, after the Roman Empire had conquered several Celtic tribes in the Iberian Peninsula (Portugal and Spain) that the Romans called the Gallaeci, Julius Caesar embarked on the nine-year Gallic Wars to defeat the Celts and various other tribal kingdoms in Gaul (modern France). Caesar wrote about the conquest of Gaul with a mix of disgust and respect for his Celtic enemies.

“In the end, Caesar makes a clear distinction between the ‘civilized’ Mediterranean world of Rome and the great unwashed Celts in Gaul, so Romans are justified in colonizing them,” says Bettina Arnold, an anthropology professor at the University of Wisconsin-Milwaukee and the founding editor of e-Keltoi: Journal of Interdisciplinary Celtic Studies.

3. Ancient Celtic burial mounds reveal a complex society.

Ancient Celtic settlement
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Ancient Celtic settlement Chysauster Village, a late Iron Age and Romano-British village of courtyard houses in Cornwall, England.

The Celts were far from savages, as evidenced by the intricate metalwork and jewelry excavated from ancient Celtic hill forts and burial mounds across Europe. One such mound near Hochdorf, Germany, held the remains of a Celtic chieftain and a wealth of artifacts pointing to a complex and stratified Celtic society.

The Hochdorf chieftain’s mound dates from 530 B.C., what archeologists call the late Hallstatt period, when Celtic culture was concentrated in Central Europe. The chieftain was laid out on a long bronze couch with wheels and dressed in gold finery including a traditional Celtic neckband called a torc. He was surrounded by ornate drinking horns and a large bronze cauldron, which still held the remains of high-proof honey mead.

Arnold says that the wheeled couch was replaced in later Celtic burial mounds by two-wheeled chariots that carried the honored dead into the afterlife. The drinking equipment points to the critical role of feasting as a sociopolitical tool to the Celts. What the Greeks and Romans described as “excessive drinking” was actually a way for Celtic elites to strengthen ties with allies. And that continued in the great beyond.

“The Celts believed in a type of BYOB afterlife,” says Arnold. “You had to bring alcohol with you and throw a big party when you got to the other side. A sign of a good leader was generosity.”

4. The Celts may have been one of the first Europeans to wear pants.

The ancient Celts were famous for their colorful wool textiles, forerunners of the famous Scottish tartan. And, while only a few tantalizing scraps of these textiles survived the centuries, historians believe that the Celts were one of the first Europeans to wear pants. They didn’t have buttons, though, so they fastened their clothing with clasps called fibulae.

5. Druids passed down histories and laws through the oral tradition.

The ancient Celts were “aliterate,” says Arnold, meaning that they actively chose not to write down their histories, sacred stories and laws, in order to safeguard the information. The Celtic religion, for example, required animal and human sacrifices to a pantheon of gods, but that esoteric knowledge was restricted to Celtic priests called Druids and passed on orally from generation to generation.

Druids were figures of great respect and honor in Celtic society and were among the few who could safely travel among warring tribes, says John Koch, a historical linguist specializing in early Celtic languages at the University of Wales. Other “learned classes” of Celts included genealogists who memorized centuries of tribal relations, those responsible for memorizing the applying the law, and “bards” who were both storytellers and folk historians.

Even though the Celtic tribes never unified politically under one kingdom, their oral traditions helped to create and maintain a cultural unity across great geographical distances. That explains why Celts were most easily identified by their shared language. Celtic languages are still spoken in parts of the UK and France, including Welsh, Irish, Scottish Gaelic, Cornish and Breton.

“Because all of the Celtic doctrines were orally transmitted, it helped to preserve linguistic uniformity,” says Koch. “The Druids and bards spoke the most prestigious version of the language and they carried it across tribal boundaries, so it didn’t fragment into a lot of different dialects.”

6. The Celtic Queen Boudicca led a bloody revolt against the Romans.

Celtic Queen Boudicca
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Boudicca, Queen of the British Iceni tribe, a Celtic tribe who led an uprising against the occupying forces of the Roman Empire.

The Romans conquered Britain in 43 A.C. under Claudius, and the Celts were slowly subjugated and Romanized. They didn’t go down without a fight, though. The legendary Celtic queen Boudicca led a bloody revolt against the Romans in 61 A.C. in which her forces destroyed the Roman stronghold of Londinium and massacred the inhabitants, according to Roman sources.

In Celtic culture, women could hold the highest position in the social hierarchy. Others were Druidesses who specialized in political prophecy and played important roles in Celtic military campaigns.

“Clearly Celtic women were occasionally allowed to take on the position of supreme authority, which was distinctly different from the Mediterranean world,” says Arnold. “The Greeks and Romans found that extremely odd.”

7. The Celts were eventually defeated by Romans, Slavs and Huns.

After the Roman conquest of most Celtic lands, Celtic culture was further trampled by Germanic tribes, Slavs and Huns during the Migration Period of roughly 300 to 600 A.C. As a result, few if any people living in Europe and the British Isles identified as Celts until the 1700s, when the Welsh linguist and scholar Edward Lhuyd recognized the similarities between languages like Welsh, Irish, Cornish and the now extinct Gaulish, and labeled them “Celtic.”

8. The embrace of a Celtic identity is relatively recent and tied to opposition to British rule.

The 19th and 20th centuries witnessed a full-blown Celtic revival in the British Isles driven by political anger over British rule in places like Ireland, Scotland and Wales. Musicians, artists and authors like William Butler Yeats proudly embraced a pre-Christian Celtic identity. But because the Celts were so much more than an Irish or Scottish phenomenon, historians remain divided over the accuracy of modern claims to Celtic heritage.

“‘Celtic’ is a descriptive term—a ‘heuristic device’ in academic lingo—shorthand for something that we can see archeologically, and we can see in the place name record, and we can see in the linguistic evidence,” says Arnold. “While it may not have actual meaning in terms of identity, it’s still useful as a descriptor.”