A druid was a member of the high-ranking priestly class in ancient Celtic cultures. Druids were religious leaders, judges, keepers of knowledge, doctors, and advisors to leaders. They did not write down their own records. Although they were said to be able to read and write, they were not allowed to write their knowledge by their beliefs. Other people from different cultures, like the Romans and Greeks, wrote about their beliefs and practices.
The first known mentions of druids come from the 4th century BCE. The most detailed description was written by Julius Caesar in his book Commentaries on the Gallic War around the 50s BCE. Other Roman writers, such as Cicero, Tacitus, and Pliny the Elder, also wrote about druids. After the Romans conquered Gaul, the Roman government under emperors Tiberius and Claudius in the 1st century CE stopped druid groups from continuing their work. 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 wise and important. Druids are often mentioned in stories from Irish mythology, like Táin Bó Cúailnge, which was written down by monks and nuns in the 12th century. Later Christian stories sometimes showed druids as magical people who resisted the spread of Christianity. During the 18th and 19th centuries, when interest in ancient Celtic culture grew, new groups formed based on ideas about druids, called Neo-Druidism. Many common beliefs about druids, which were based on misunderstandings from 18th-century scholars, have been corrected by more recent research.
Etymology
The word "druid" in modern English comes from the French word "druide," which in turn comes from the Latin word "druida" (found only in plural as "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 Brythonic.
The Gaulish word "druides" is similar to the Old Irish word "druí" (plural "druíd," meaning "magician or wizard"). It may also be related to the Middle Welsh word "dryw," meaning "seer," as found in the Book of Taliesin. In both Irish and Welsh, "druí" and "dryw" could sometimes refer to the wren, a bird considered prophetic in those traditions. The Middle Welsh word "derwydd" ("seer") and the Old Breton word "dorguid" ("prophetic, magical") show similar patterns. These might reflect a change in the Proto-Celtic word dru-wid- to daru-wid- (based on the Celtic word for "oak tree") or come from *do-are-wid- ("who sees beyond").
All these forms come from a Proto-Celtic noun reconstructed as dru-wid-s (plural dru-wid-es). The second part of the word is generally from the Proto-Indo-European verb weyd- ("see, know"). The origin of the first part has been debated. Most scholars believe it comes from Proto-Indo-European derw- ≈ *dru- ("oak"), which metaphorically also meant "strong or firm." This led to meanings such as "oak-knower" or "someone who knows trees." Some scholars suggest it might mean "very wise." This connection was noted by Pliny, a Roman writer from the 1st century, who compared the first part to the Greek word "drŷs" ("oak").
Practices and doctrines
Ancient and medieval writers describe the religious duties and social roles of druids.
Greco-Roman and Irish sources agree that druids were important in pagan Celtic society. Julius Caesar wrote that druids were among the two most important groups in the region, along with the nobles. They organized religious worship, sacrifices, and divination, and handled legal matters in Gallic, British, and Irish societies. Caesar noted that druids were not required to serve in the military or pay taxes, and they could exclude people from religious events, making them outcasts. Other writers, Diodorus Siculus and Strabo, wrote that druids were so respected that they could stop battles by intervening between opposing armies.
Diodorus described druids as "philosophers" and "learned in religious affairs," while Strabo said their knowledge included natural and moral philosophy. Ammianus Marcellinus listed them as experts in "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, using methods like augury and guesswork to make predictions.
Druidic knowledge was passed down orally and included many memorized verses. Caesar noted that studying to become a druid could take up to twenty years. No ancient verses from druidic teachings are known to have survived. The Gauls had a written language using Greek letters, though by Caesar’s time, they used Latin letters instead.
Caesar believed that druids avoided writing to protect their knowledge and improve memory. He wrote that many young people chose to study with druids, and others were sent by their families because of the druids’ high status.
Greek and Roman writers often described druids as performing human sacrifices. Caesar said criminals were preferred as victims, but if none were available, innocent people were used. One method involved burning victims inside a large wooden structure, now called a wicker man. A 10th-century text, the Commenta Bernensia, described sacrifices to gods as drowning, hanging, and burning.
Diodorus Siculus wrote that druids acted as intermediaries between people and gods, and that they used animal sacrifices and bird behavior to predict the future. He also described a ritual where a human victim was stabbed, and their movements and blood were observed to read the future.
Archaeological findings, such as mass graves in Gaul, have been linked to human sacrifice. Some scholars, like Jean-Louis Brunaux, believed these were places of sacrifice, while others, like Martin Brown, thought the remains were of honored warriors. Some historians question whether Roman and Greek writers accurately described druid practices, suggesting these accounts may have reflected Roman biases.
Nora Chadwick, an expert in medieval literature, argued that druids were philosophers and that claims of human sacrifice were Roman propaganda.
Alexander Cornelius Polyhistor called druids "philosophers" and noted their belief in the immortality of the soul and reincarnation, which he compared to the Pythagorean doctrine.
Julius Caesar wrote that druid education focused on teaching the immortality of the soul, which helped people face death without fear. He also mentioned their studies of stars, geography, and natural philosophy.
Diodorus Siculus, writing in 36 BCE, described druids following the Pythagorean belief that souls are immortal and return to new bodies after a set time. Caesar noted that druids believed the tribe’s ancestor was a god called "Dispater," meaning "Father Dis."
Diogenes Laertius, writing in the 3rd century CE, wrote that druids used riddles and sayings to teach respect for the gods and moral behavior.
Druids in mythology
Druids are important figures in Irish folklore. They often served as religious advisors and counselors to kings and lords. They had special powers, like the ability to predict the future and perform other magical acts. One well-known druid was Cathbad, who worked in the court of King Conchobar mac Nessa of Ulster. Cathbad is famous for his ability to foretell events. In the story of Deirdre of the Sorrows, a key character in the Ulster Cycle, Cathbad predicted that Deirdre would grow up to be very beautiful. He also warned that kings and lords would fight over her, leading to much bloodshed, and that Ulster's greatest warriors would be forced into exile because of her. The king ignored this prophecy, but it later came true.
Another important druid was Amergin Glúingel, a bard and judge for the Milesians in the Mythological Cycle. The Milesians wanted to take control of Ireland from the Tuatha Dé Danann. As the Milesians approached, the druids of the Tuatha Dé Danann created a powerful storm to stop their ships from landing. Amergin responded by calling upon the spirit of Ireland itself. He chanted a powerful song, now known as The Song of Amergin. After successfully landing, Amergin helped his royal brothers conquer Ireland and divide the land among them. He was later honored as Chief Ollam of Ireland.
Other druids from Irish mythology 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
In Irish mythology, there are many female druids who have important roles similar to those of male druids. The Irish language has several names for female druids, such as bandruí ("woman-druid"), mentioned in stories like Táin Bó Cúailnge. Another example is Bodhmall, who appears in the Fenian Cycle and was a caretaker for Fionn mac Cumhaill during his childhood. Tlachtga, the daughter of the druid Mug Ruith, is connected 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 key role in a folktale where the Fomorian warrior Balor tries to stop a prophecy that he will be killed by his grandson. To do this, Balor imprisons his daughter Eithne on Tory Island to keep her away from men. Bé Chuille, the daughter of the woodland goddess Flidais, appears in a story from the Metrical Dindshenchas. She joins three other Tuatha Dé to defeat the Greek witch Carman. Other bandrúi include Relbeo, a Nemedian druid described in The Book of Invasions as the daughter of the king of Greece 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 Artemidorus Ephesius and Strabo, mentioned the Gallizenae (or Gallisenae), who were virgin priestesses living on Île de Sein near Pointe du Raz in western Brittany. Strabo wrote that their island was closed to men, but the women traveled to the mainland to meet their husbands. It is unknown which gods they worshipped. Pomponius Mela described the Gallizenae as both advisors and healers who could control the sea and wind, change their forms into animals, cure diseases, and predict the future. They only helped travelers who sought their guidance.
According to The Historia Augusta, the Roman emperor Alexander Severus received a prophecy about his death from a Gallic druidess (druiada). The text also mentions that Emperor Aurelian asked druidesses about the fate of his descendants, and they predicted that Claudius II would succeed him. Flavius Vopiscus recorded that Emperor Diocletian received a prophecy from a druidess of the Tungri.
Sources on druid beliefs and practices
The earliest known written records about druids come from ancient Greece and Rome. Archaeologist Stuart Piggott compared how these classical writers viewed druids to how Europeans in the 15th and 18th centuries saw societies in distant lands, like the Americas and the South Sea Islands. He noted that both groups believed these societies were less advanced in technology and governance.
Historian Nora Chadwick divided classical descriptions of druids into two groups. The first, called the "Posidonian" tradition after the writer Posidonius, focused on criticizing Iron Age societies in Western Europe, calling them "barbaric." The second group, called the "Alexandrian" tradition after the Egyptian city of Alexandria, showed more interest in and respect for these cultures. Piggott linked this to ideas called "hard primitivism" and "soft primitivism" studied by historians Arthur Oncken Lovejoy and Franz Boas.
Some scholars argue that classical accounts of druids may not be reliable and could be fictional. They suggest that druids might have been invented by classical writers to describe "barbaric" outsiders, helping justify Roman expansion into these regions.
The earliest surviving records of druids come from two Greek texts written around 300 BCE: a philosophy history by Sotion of Alexandria and a magic study often linked to Aristotle. These texts are lost, but parts of them appear in a 2nd-century CE work called Vitae by Diogenes Laërtius.
In Vitae, it is written: "Some say that the study of philosophy began with the barbarians. Among the Persians, there were the Magi; among the Babylonians or Assyrians, the Chaldaei; among the Indians, the Gymnosophistae; and among the Celts and Gauls, people called druids and semnothei, as Aristotle relates in his book on magic, and Sotion in the twenty-third book of his Succession of Philosophers."
Later Greek and Roman texts from the 3rd century BCE mention "barbarian philosophers," possibly referring to the Gaulish druids.
The first detailed surviving description of druids comes from Julius Caesar’s Commentarii de Bello Gallico, written in the 50s or 40s BCE. As a Roman general planning to conquer Gaul and Britain, Caesar described druids as people who handled religious rituals, sacrifices, and answered questions about ceremonies. He said they were respected in Gaulish society, along with a class called the equites. They acted as judges and followed a leader who ruled until death, after which a new leader was chosen. They met annually at a sacred place in the territory of the Carnutes, believed to be the center of Gaul. Caesar claimed Britain was the center of druidic learning and that druids were not found among German tribes east of the Rhine. He noted that young men trained to become druids had to memorize religious teachings, which included beliefs about the soul moving to new bodies after death. They studied stars, the cosmos, nature, and the power of gods, suggesting they were involved in astronomy and theology. Caesar also said druids supervised human sacrifices, often using criminals, and burned them in a wicker structure.
Modern historians have criticized Caesar’s account as possibly inaccurate. For example, Fustel de Coulanges pointed out that Caesar never mentioned druids in his accounts of conquering Gaul, nor did Aulus Hirtius, who continued Caesar’s writings after his death. Some scholars, like Ronald Hutton, believe Caesar portrayed druids as both civilized (learned and pious) and barbaric (performing sacrifices) to justify Roman rule. Others, like Sean Dunham, suggest Caesar compared druids to Roman senators. Daphne Nash argued Caesar may have exaggerated the centralization of druidic leadership and its connection to Britain.
Other historians think Caesar’s account might be more accurate. Norman J. DeWitt suggested Caesar described an idealized version of druidic society from the 2nd century BCE, before major conflicts disrupted Gaul. John Creighton noted that druidic 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 about druids, even if he may have exaggerated details to support Roman expansion.
Other classical writers also wrote about druids. Cicero, Caesar’s contemporary, mentioned meeting a Gallic druid named Divitiacus of the Aedui tribe, who was knowledgeable about nature and practiced divination. However, Caesar referred to him as Diviciacus and never called him a druid, instead presenting him as a political and military leader.
Diodorus Siculus, writing in 36 BCE, described druids (or drouidas) as philosophers and theologians, noting their roles alongside poets and singers.
Archaeology
As historian Jane Webster noted, "individual druids … are unlikely to be identified archaeologically." A. P. Fitzpatrick studied symbols he believed were related to the stars on late Iron Age swords. He found it difficult to connect these physical objects, even the Coligny calendar, to druidic culture.
Some archaeologists have tried to connect discoveries with written records about druids. Anne Ross linked evidence of human sacrifice in Celtic society, such as the Lindow Man bog body, to Greco-Roman descriptions of sacrifices led by druids. Miranda Aldhouse-Green, a professor at Cardiff University, pointed out that Suetonius’s army traveled near the Lindow Man’s site while dealing with Boudicca. She suggested the sacrifice might have been connected to this event. A 1996 discovery of 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 unique headband. The headband is too thin to be part of a leather helmet. It is 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. This headdress resembles images of Romano-British priests from later centuries. Some archaeologists have suggested the man might have been a religious official, possibly a druid.
History of reception
During the Gallic Wars from 58 to 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 from centuries after this time describe how the new rulers of Roman Gaul introduced laws to remove the druids from the region. Pliny the Elder, who wrote in the 70s CE, stated that Emperor Tiberius (ruled 14–37 CE) passed laws that banned not only druidic practices but also other native soothsayers and healers. Pliny believed this would stop human sacrifices in Gaul. Suetonius, writing in the 2nd century CE, described a different account: Rome’s first 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 completely stopped druidic religious practices.
The strongest evidence of a druidic tradition in the British Isles comes from the word druwid-, which appears 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 Christianization of the region, which was completed by the 7th century at the latest. However, the roles of bards and "seers" (Welsh: dryw) continued in medieval Wales until the 13th century.
In 1764, Minister Macauley reported finding five druidic altars, including a large circle of stones near Stallir House on Boreray, near the westernmost settlement of the UK, St. Kilda.
Classics professor Phillip Freeman noted that the Historia Augusta, a collection of imperial biographies from the 4th century CE, mentions "dryades" (translated as "druidesses") in three short passages about Gaulish women. Freeman explained that these women might not have been direct descendants of the druids, but they show that the role of prophecy continued among native people in Roman Gaul. Female druids are also mentioned 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, gives one of the few accounts of possible druidic survival in Britain after the Romans arrived. Nennius wrote that after being excommunicated by Germanus of Auxerre, the British leader Vortigern invited twelve druids to help him.
In stories about saints and martyrs, druids are described as magicians and diviners. In Adamnan’s life of Saint Columba, two druids act as tutors to the daughters of Lóegaire mac Néill, the High King of Ireland, when Saint Patrick arrives. They try to stop 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 one of the armies, though the exact meaning of this phrase is unclear. Irish druids are said to have had a unique style of cutting their hair. The word druí was used to describe people called magus in Latin, and in one passage, Saint Columba refers to Jesus as his druid. A story about Saint Beuno mentions that when he died, he had a vision of "all the saints and druids."
In the life of Saint Martin of Tours, Sulpicius Severus wrote that Martin saw a peasant funeral with a body wrapped in a winding sheet. He mistook this for druidic rituals of sacrifice, thinking the people were carrying images of demons covered in white cloth. Martin stopped the procession by raising his cross, causing the people to stiffen and spin in confusion. After realizing his mistake, Martin allowed them to continue.
From the 18th century, interest in druids grew in England and Wales. John Aubrey was the first modern writer to incorrectly link Stonehenge and other ancient monuments to the druids. William Stukeley later popularized this idea. It is falsely believed that John Toland started the Ancient Druid Order, but historian Ronald Hutton found that the order was actually founded by George Watson MacGregor Reid in 1909. 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 fake stories about the ancient Scottish poet Ossian, not from druids. John Toland was influenced by Aubrey’s theories about Stonehenge and wrote a book about the monument without giving Aubrey credit. 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 reading The Gallic Wars, that druids were the main group resisting the Romans in Gaul was studied and rejected before World War II, though it remains in folk history.
Druids became popular in stories during the Romantic period. In Chateaubriand’s novel Les Martyrs (1809), a druid priestess falls in love with a Roman soldier. Though the story focuses on Christianity defeating paganism, the setting influenced later works. In opera, druids appeared in the 19th century. Giovanni Pacini’s La Sacerdotessa d'Irminsul (1817) and Vincenzo Bellini’s Norma (1831) used druidic themes. Norma was a failure at its premiere but later became a hit in London. The story reused elements from earlier druidic background material. The main character in Norma is a chaste goddess, the moon goddess worshipped in the "grove of the Irmin statue."
A key figure in the 19th-century revival of druidic ideas was Welshman Edward Williams, known as Iolo Morganwg. His writings, published after his death as The Iolo Manuscripts (1849) and Barddas (1862), are not trusted by modern scholars. Williams claimed he collected ancient knowledge from a group he called the "Gorsedd of Bards of the Isles of Britain." However, his work is considered unreliable.