A druid was a member of the important priest class in ancient Celtic cultures. Druids held many roles, including religious leaders, judges, keepers of knowledge, doctors, and advisors to leaders. They did not leave written records. Although they were known to be literate, their teachings were not written down because of religious rules. Other cultures, like the Romans and Greeks, described their beliefs and practices in detail.
The first known mentions of druids date to the 4th century BCE. The most detailed early description comes from Julius Caesar’s writings in the 50s BCE. Roman writers such as Cicero, Tacitus, and Pliny the Elder also wrote about them. After the Roman invasion of Gaul, the Roman government under emperors Tiberius and Claudius in the 1st century CE suppressed druid groups. By the 2nd century, there were no more written records about druids.
In about 750 CE, the word "druid" appeared in a poem by Blathmac, who compared Jesus to a druid, saying Jesus was more knowledgeable and wise. Druids are often mentioned in stories from Irish mythology, such as "Táin Bó Cúailnge," written by monks and nuns of the Celtic Church in the 12th century. Later Christian stories often portrayed druids as sorcerers who resisted the spread of Christianity. During the Celtic revival in the 18th and 19th centuries, groups based on ideas about ancient druids formed, a movement called Neo-Druidism. Many common beliefs about druids, influenced by misunderstandings from 18th-century scholars, have been corrected by more recent research.
Etymology
The modern English word "druid" comes from the French word "druide," which is from the Latin word "druida" (used only in the plural form "druides"). This Latin word was likely borrowed from the Gaulish language, which used "druid-." The Old English word "drȳ," meaning a magician or wizard, was borrowed from Celtic languages, possibly from Irish or from Brythonic.
The Gaulish word "druides" is related to the Old Irish word "druí" (plural "druíd," meaning "magician or wizard") and may also be connected to the Middle Welsh word "dryw," which means "seer" and appears in the Book of Taliesin. In both Irish and Welsh, "druí" and "dryw" could sometimes refer to the wren, a bird considered to have special knowledge in these traditions. The Middle Welsh word "derwydd" (meaning "seer") and the Old Breton word "dorguid" (meaning "prophetic or magical") are similar in form. These words may reflect a change in the ancient Celtic language, where the word dru-wid- (meaning "seer") was altered to daru-wid- (based on the Celtic word daru- meaning "oak tree") or may come from do-are-wid- (meaning "who sees beyond").
All these words are believed to come from a reconstructed ancient Celtic word dru-wid-s (plural dru-wid-es). The second part of this word, "-wid," is from the ancient Proto-Indo-European verb weyd- ("to see or know"). The first part, "dru," has been debated by scholars. Most believe it comes from the Proto-Indo-European word derw- (similar to *dru-), meaning "oak tree," which also meant "strong or firm." Based on this, the word has been interpreted as "someone who knows about oaks," "someone who knows trees," possibly "someone who knows the world tree," or "a priest with strong insight." This idea was noted by a writer named Pliny in the first century, who compared "dru" to the Greek word "drŷs" ("oak"). Some scholars, however, suggest that "dru" might be a prefix meaning "very" or "extremely," giving the word the meaning "the very wise."
Practices and doctrines
Ancient and medieval writers provide information about the religious duties and social roles of druids.
Greek, Roman, and local Irish sources agree that druids were important in pagan Celtic society. Julius Caesar wrote that druids were one of the two most important groups in the region, along with the nobles. They organized religious worship, sacrifices, and divination, and they helped with legal matters in Gallic, British, and Irish societies. Caesar noted that druids did not serve in the military or pay taxes, and they could exclude people from religious events, making them outcasts. Other writers, Diodorus Siculus and Strabo, described how respected druids were, saying that if they intervened between two armies, they could stop a battle.
Diodorus called druids "philosophers" and "learned in religious matters," while Strabo said their knowledge included natural and moral philosophy. Ammianus Marcellinus described them as people who studied "obscure and profound subjects." Pomponius Mela was the first to mention that druid education was secret and took place in caves and forests. Cicero wrote about a Gaulish druid who claimed to understand nature, a knowledge the Greeks called "physiologia," and who made predictions using signs and guesses.
Druidic knowledge included many memorized verses. Caesar noted that it could take up to twenty years to complete their training. However, no ancient verses from druidic teachings are known to have survived. All instruction was oral, though the Gauls had a written language using Greek letters. By Caesar’s time, Gaulish writing had shifted to Latin letters.
Caesar believed that druids avoided writing their knowledge to keep it special and to improve their memory. He wrote that many young men sought druid training, and some were sent by their families because of the druids’ high status.
Greek and Roman writers often described druids as people who performed human sacrifices. Caesar said criminals were preferred as victims, but if criminals were not available, innocent people could be used. One recorded method involved burning victims alive inside a large wooden structure, now called a "wicker man." A 10th-century text, Commenta Bernensia, described sacrifices to gods as drowning, hanging, and burning.
Diodorus Siculus wrote that druids were required to oversee sacrifices because they acted as intermediaries between people and gods. He emphasized the role of prophets in rituals.
Archaeological findings in western Europe, such as mass graves in Gaul, have been used to support the idea that Iron Age Celts practiced human sacrifice. Jean-Louis Brunaux, who studied these sites, believed the graves were places of sacrifice to a war god. However, Martin Brown suggested the bodies might belong to honored warriors buried in a sanctuary. Some historians question whether Roman and Greek writers accurately described druids, as they may have exaggerated foreign customs to highlight their own cultural superiority.
Nora Chadwick, an expert on medieval Welsh and Irish literature, believed druids were philosophers and argued that claims about their involvement in human sacrifice were Roman propaganda.
Alexander Cornelius Polyhistor called druids "philosophers" and described their beliefs about the soul’s immortality and reincarnation as "Pythagorean." Caesar also noted druidic teachings about the soul’s journey after death.
Diodorus Siculus, writing in 36 BCE, described druids following the "Pythagorean doctrine," which taught that souls are immortal and return to new bodies after a set time. In 1928, Donald A. Mackenzie suggested that Buddhist missionaries might have traveled to Europe from India. Caesar wrote that druids believed the tribe’s ancestor was a god he called "Dispater," meaning "Father Dis."
Diogenes Laertius, writing in the 3rd century CE, noted that druids used riddles and cryptic sayings to teach that gods should be honored, evil should be avoided, and strong, moral behavior should be practiced.
Druids in mythology
Druids are important figures in Irish stories, often serving as religious advisors to kings and lords. They are known for their ability to predict the future and perform other magical tasks. One well-known druid is Cathbad, who was the chief druid in the court of King Conchobar mac Nessa of Ulster. Cathbad appears in many stories, most of which describe his skill in predicting events. In the tale of Deirdre of the Sorrows, a famous tragic character from the Ulster Cycle, Cathbad told the court that Deirdre would grow up to be very beautiful. He also predicted that kings and lords would fight over her, that much blood would be spilled because of her, and that Ulster’s three greatest warriors would be forced into exile due to her. The king ignored this prophecy, but it came true.
Another important druid from Irish mythology is Amergin Glúingel, a poet and judge for the Milesians in the Mythological Cycle. The Milesians tried to take over Ireland from the Tuatha Dé Danann, but the druids of the Tuatha Dé Danann used a magical storm to stop their ships from landing. Amergin then called upon the spirit of Ireland, singing a powerful spell known as The Song of Amergin. After successfully landing, he helped divide the land among his royal brothers during the conquest of Ireland and earned the title Chief Ollam of Ireland.
Other druids from Irish myths include Tadg mac Nuadat, who appears in the Fenian Cycle, and Mug Ruith, a blind druid from Munster known for his great power.
Female druids
Irish mythology includes many female druids who held important cultural and religious roles, similar to those of male druids. The Irish language has several names for female druids, such as "bandruí," which means "woman-druid." This term appears in stories like Táin Bó Cúailnge. Another example is Bodhmall, who is part of the Fenian Cycle, a group of ancient Irish tales, and was one of Fionn mac Cumhaill's caretakers during his childhood. Tlachtga, the daughter of the druid Mug Ruith, is linked to the Hill of Ward, a place where festivals were held in her honor during the Middle Ages.
Biróg, a bandruí of the Tuatha Dé Danann, plays a major role in a folktale where the Fomorian warrior Balor tries to stop a prophecy that he would be killed by his grandson. To do this, he imprisons his daughter Eithne on Tory Island to keep her away from men. Bé Chuille, the daughter of the goddess Flidais, appears in a story from the Metrical Dindshenchas, a collection of old Irish tales. She joins other Tuatha Dé members to defeat the evil Greek witch Carman. Other bandrúi include Relbeo, a Nemedian druid from The Book of Invasions, who is described as the daughter of a Greek king and the mother of Fergus Lethderg and Alma One-Tooth. Dornoll, a bandrúi in Scotland, trained warriors like Laegaire and Conall. She was the daughter of Domnall Mildemail.
Classical writers, such as the Greek geographer Artemidorus Ephesius and the historian Strabo, mentioned the Gallizenae, or Gallisenae, who were virgin priestesses living on Île de Sein, an island near Pointe du Raz in western Brittany. Strabo wrote that the island was closed to men, but the women visited the mainland to meet their husbands. It is unknown which gods they honored. According to Pomponius Mela, the Gallizenae served as advisors and healers.
The Historia Augusta records that the Roman emperor Alexander Severus received a prophecy about his death from a Gallic druidess called druiada. The same text notes that the emperor Aurelian asked druidesses about the future of his descendants, and they predicted that Claudius II would succeed him. Flavius Vopiscus also wrote that the Roman emperor Diocletian received a prophecy from a druidess of the Tungri people.
Sources on druid beliefs and practices
The earliest written records about druids come from ancient Greece and Rome. Archaeologist Stuart Piggott compared how these ancient writers viewed druids to how Europeans in the 15th and 18th centuries saw societies in other parts of the world, like the Americas and the South Sea Islands. He noted that both groups saw these societies as less technologically and socially advanced, a view called "primitivism."
Historian Nora Chadwick, later followed by Piggott, divided ancient writings about druids into two groups. The first group, called the "Posidonian" tradition after the writer Posidonius, criticized the Iron Age societies of Western Europe, calling them "barbaric." The second group, called the "Alexandrian" group, focused on the learning traditions of Alexandria, Egypt, and showed more respect and admiration for these societies. Piggott linked this to two ideas: "hard primitivism" and "soft primitivism," which were studied by historians Arthur Oncken Lovejoy and Franz Boas.
Some scholars believe the ancient accounts of druids may not be reliable and could be fictional. They suggest that the idea of druids was created by Greek and Roman writers to describe "barbaric" outsiders, which helped justify the expansion of the Roman Empire.
The earliest known records of druids appear in two Greek texts from around 300 BCE: a philosophical history by Sotion of Alexandria and a study of magic attributed to Aristotle. These texts are now lost but were quoted by the 2nd-century writer Diogenes Laërtius in his work Vitae.
Greek and Roman writings from the 3rd century BCE mention "barbarian philosophers," which may refer to the Gaulish druids.
The first surviving detailed description of druids comes from Julius Caesar’s Commentarii de Bello Gallico, written in the 50s or 40s BCE. As a Roman general aiming to conquer Gaul and Britain, Caesar described druids as people who focused on religious rituals, sacrifices, and interpreting spiritual matters. He said they were respected in Gaulish society, along with the equites (a privileged class in Rome). They also acted as judges.
Caesar wrote that druids followed a single leader until his death, after which a new leader was chosen by voting or conflict. To resolve disputes, they met annually at a sacred site in the territory of the Carnutes, believed to be the center of Gaul. They saw Britain as the heart of druidic learning and claimed druids were not found among the German tribes east of the Rhine. Young men trained to become druids had to memorize religious teachings, including the belief that souls move from one body to another after death. They studied stars, the cosmos, nature, and gods, showing knowledge of astronomy, theology, and cosmology. Caesar also said druids oversaw human sacrifices, often using criminals, and that victims were burned inside a wicker man.
Modern historians have questioned the accuracy of Caesar’s account. Some, like Fustel de Coulanges, noted that Caesar never mentioned druids in his descriptions of conquering Gaul, nor did Aulus Hirtius, who continued Caesar’s writings. Historian Ronald Hutton argued that Caesar portrayed druids as both civilized (knowledgeable and religious) and barbaric (practicing human sacrifice) to justify Roman rule. Others, like Sean Dunham, suggested Caesar compared druids to Roman senators. Daphne Nash believed Caesar exaggerated the centralization of druid leadership and its ties to Britain.
Some historians believe Caesar’s account might be more accurate. Norman J. DeWitt suggested Caesar described an idealized version of druid society from the 2nd century BCE, before Gaul was weakened by wars. John Creighton noted druid influence in Britain may have declined by the mid-1st century BCE due to new power structures. Miranda Aldhouse-Green (2010) argued Caesar’s account is one of the most reliable sources on druids, even if he may have exaggerated details to support Roman expansion.
Other classical writers also wrote about druids. Cicero, Caesar’s contemporary, met a Gallic druid named Divitiacus of the Aedui tribe, who was knowledgeable about nature and practiced augury. However, Caesar did not call him a druid and instead described him as a political and military leader.
Diodorus Siculus, writing in 36 BCE, described druids (called drouidas) as philosophers and theologians, alongside bardous (bards) who were poets and singers. Strabo, writing in the 20s CE, listed three respected groups among the Gauls: bardoi (bards), o'vateis (diviners), and druidai (druids) who studied moral philosophy. The Roman writer Tacitus also wrote about druids, though the text is incomplete.
Archaeology
As historian Jane Webster noted, "individual druids … are unlikely to be identified archaeologically." A. P. Fitzpatrick studied what he thought were symbols related to stars or the sky on late Iron Age swords. He found it difficult to connect any physical objects, even the Coligny calendar, to druidic culture.
Some archaeologists have tried to connect discoveries with written descriptions of druids. Anne Ross linked evidence of human sacrifice in Celtic society, such as the Lindow Man bog body, to Roman and Greek writings that described druids overseeing such rituals. Miranda Aldhouse-Green, a professor at Cardiff University, pointed out that Suetonius’s army likely passed near the site during their journey to deal with Boudicca. She suggested the sacrifice might have been connected to this event. In 1996, a skeleton buried with advanced medical tools and possibly religious items was nicknamed the "Druid of Colchester."
An excavation in Deal, Kent, uncovered the "Deal Warrior," a man buried around 200–150 BCE with a sword, shield, and a rare headband. The headband was too thin to be part of a leather helmet. It was made of bronze, with a wide band around the head and a thin strip crossing the top horizontally. Hair was found on the metal, showing it was worn directly on the head without padding. The style of the headdress resembles images of Romano-British priests from centuries later. This has led some archaeologists to suggest the man might have been a religious official, possibly a druid.
History of reception
In the Gallic Wars of 58–51 BCE, the Roman army, led by Julius Caesar, conquered the many tribal chiefdoms of Gaul and added it to the Roman Republic. Later accounts described how the Romans introduced laws to remove the druids from Gaul. Pliny the Elder, writing in the 70s CE, stated that Emperor Tiberius (ruled 14–37 CE) passed laws banning druidic practices and other native soothsayers and healers. Pliny believed this would stop human sacrifice in Gaul. Suetonius, writing in the 2nd century CE, claimed that Emperor Augustus (ruled 27 BCE–14 CE) made it illegal for anyone to be both a druid and a Roman citizen. Later, Emperor Claudius (ruled 41–54 CE) passed a law that "thoroughly suppressed" the druids by banning their religious practices.
The strongest evidence of a druidic tradition in the British Isles is the similar word druwid- found in Insular Celtic languages. In Old Irish, the word druídecht means "magic," and in Welsh, *dryw means "seer."
The druids, who were a priestly group, disappeared in Wales after the spread of Christianity by the 7th century. However, roles like the bard and the "seer" (Welsh: *dryw) continued in medieval Wales until the 13th century.
Minister Macauley (1764) reported finding five druidic altars, including a large circle of stones near the Stallir House on Boreray, near the westernmost settlement of the UK, St. Kilda.
Classics professor Phillip Freeman discussed references to "dryades," which he translated as "druidesses." He noted that the *Historia Augusta, a collection of imperial biographies from the 4th century CE, mentions three short passages about Gaulish women called "dryades." These women may not have been direct descendants of the druids, but they show that prophecy remained part of native traditions in Roman Gaul. Female druids also appear in later Irish mythology, such as in the legend of Fionn mac Cumhaill, who was raised by the woman druid Bodhmall and another wise-woman.
The story of Vortigern, as told by Nennius, describes one of the few possible examples of druidic survival in Britain after the Romans arrived. Vortigern invited twelve druids to help him after being excommunicated by Germanus of Auxerre.
In stories about saints and martyrs, druids are shown as magicians and diviners. In Adamnan’s life of Columba, two druids act as tutors to the daughters of Lóegaire mac Néill, the High King of Ireland. They try to stop Saint Patrick and Saint Columba by creating clouds and mist. Before the Battle of Culdremne in 561 CE, a druid made an airbe drtiad ("fence of protection") around an army, though the exact meaning of this phrase is unclear. Irish druids had a unique style of cutting their hair. The word druí was used to translate the Latin word magus. In one passage, Saint Columba refers to Jesus as his druid. A story about Saint Beuno mentions that he saw "all the saints and druids" in a vision when he died.
Sulpicius Severus’s life of Martin of Tours describes how Martin mistook a peasant funeral for druidic sacrifice rituals. Martin stopped the procession by showing his cross, causing the people to freeze and whirl in confusion. He then allowed them to continue.
From the 18th century, interest in druids revived in England and Wales. John Aubrey (1626–1697) was the first modern writer to incorrectly link Stonehenge and other large stone monuments to the druids. William Stukeley (1687–1765) later popularized this idea. John Toland (1670–1722) is wrongly believed to have founded the Ancient Druid Order, but historian Ronald Hutton found that the order was actually created in 1909 by George Watson MacGregor Reid. The order never used the title "Archdruid" and falsely claimed William Blake was its "Chosen Chief" from 1799–1827, despite no evidence in Blake’s work. Blake’s mystical ideas came from other sources, not druidism. Toland was influenced by Aubrey’s theories but did not credit him. The roles of bards in 10th-century Wales were established by Hywel Dda, and the idea that druids were their predecessors arose in the 18th century.
The 19th-century belief, based on the *Gallic Wars, that druids led resistance against the Romans was later dismissed, though it remains in folk history.
Druids became widely known in popular culture during the Romantic era. In 1809, Chateaubriand’s novel Les Martyrs told the story of a druid priestess and a Roman soldier. Opera also reflected this interest: In 1817, Giovanni Pacini’s opera La Sacerdotessa d'Irminsul featured a druid priestess. Vincenzo Bellini’s opera *Norma was a failure at La Scala in