A druid was a member of a high-ranking group of priests in ancient Celtic cultures. Druids were religious leaders, judges, keepers of knowledge, doctors, and advisors to leaders. They did not write down their own knowledge. Although they were believed to be able to read and write, their religious beliefs may have stopped them from recording their knowledge in writing. Other cultures, like the Romans and Greeks, described their beliefs and practices in detail.
The first known mentions of druids come from the 4th century BCE. The most detailed description is from Julius Caesar’s book about the Gallic Wars, written in the 50s BCE. Other Roman writers, such as Cicero, Tacitus, and Pliny the Elder, also wrote about druids. After the Romans invaded Gaul, the Roman government, under emperors Tiberius and Claudius in the 1st century CE, stopped the druids 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 wrote about Jesus, saying he was "better than a prophet, more knowledgeable than every druid, a king who was a bishop and a complete sage." Druids are often mentioned in stories from Irish mythology, first written by monks and nuns of the Celtic Church, such as the "Táin Bó Cúailnge" (12th century). Later Christian stories often showed druids as sorcerers who opposed missionaries bringing Christianity. During the 18th and 19th centuries, when interest in ancient Celtic culture grew, groups based on ideas about druids were formed, a movement called Neo-Druidism. Many old beliefs about druids, based on incorrect ideas from 18th-century scholars, have been replaced by more recent research.
Etymology
The word "druid" in modern English comes from the French word "druide," which itself is from the Latin word "druida" (only found 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 Brythonic.
The Gaulish word "druides" is related to the Old Irish word "druí" (plural "druíd," meaning "magician" or "wizard"). It may also be connected 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 to have prophetic powers in these traditions. The Middle Welsh word "derwydd" (meaning "seer") and the Old Breton word "dorguid" (meaning "prophetic" or "magical") show similar patterns. These words might reflect a change in the Proto-Celtic word "dru-wid-" (plural "dru-wid-es"), which was later modified to "daru-wid-" (based on the Celtic word for "oak tree") or could come from "do-are-wid-" (meaning "who sees beyond").
All these words are believed to come from a Proto-Celtic noun "dru-wid-s" (plural "dru-wid-es"). The second part of the word likely comes from the Proto-Indo-European verb "weyd-" (meaning "to see" or "to know"). The first part of the word has been debated by scholars. Most believe it comes from the Proto-Indo-European word "derw-" or "*dru-" (meaning "oak tree"), which also meant "strong" or "firm" in a metaphorical way. This led to interpretations such as "oak-knower," "one who knows trees," or "one with strong insight." This connection was noted by the Roman writer Pliny in the 1st century, who compared it to the Greek word "drŷs" (meaning "oak"). Some scholars, however, suggest the first part might be an intensifier, meaning "very wise."
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 judged legal matters in Gallic, British, and Irish societies. Caesar noted that druids did not serve in the military or pay taxes and had the power to exclude people from religious events, making them social outcasts. Other writers, Diodorus Siculus and Strabo, wrote that druids were so respected that they could stop battles if they intervened between armies.
Diodorus described druids as "philosophers" and "learned in religious matters." Strabo said their knowledge included natural and moral philosophy, while Ammianus Marcellinus called them investigators of "obscure and profound subjects." Pomponius Mela was the first to write that druid education was secret and took place in caves and forests. Cicero mentioned a Gaulish druid who claimed knowledge of nature, similar to Greek "physiologia," and made predictions using signs from animals or the environment.
Druidic knowledge included memorizing many verses. Caesar wrote that it could take up to twenty years to complete their training. However, no ancient druidic verses are known to have survived, as all instruction was oral. Caesar noted that the Gauls had a written language using Greek letters, though by his time, they had shifted to Latin script. Caesar believed druids avoided writing to keep their knowledge private and to strengthen their memory. He wrote that many young men chose to study with druids, while others were sent by their families due to the druids' high status.
Greek and Roman writers often described druids as practicing human sacrifice. Caesar wrote that criminals were preferred as victims, but if criminals were scarce, innocent people were used. One method involved burning victims alive inside a large wooden figure, now called a "wicker man." A 10th-century text, Commenta Bernensia, described sacrifices to gods like Teutates, Esus, and Taranis as drowning, hanging, and burning, respectively.
Diodorus Siculus wrote that druids acted as intermediaries between people and gods, and that they used animal sacrifices and bird signs to predict the future. He noted that druids sometimes used human victims to read the future by observing their reactions.
Archaeological findings in western Europe, such as mass graves in Gaul, have been linked to human sacrifice. However, some historians debate this, suggesting the remains might belong to honored warriors instead. Some scholars question whether Roman and Greek writers accurately described druids, noting that these cultures often portrayed outsiders as "barbaric" to highlight their own superiority.
Nora Chadwick, an expert in medieval literature, believed druids were philosophers and not involved in human sacrifice, calling such claims Roman propaganda. Alexander Cornelius Polyhistor called druids "philosophers" and noted their belief in the soul's immortality and reincarnation, similar to the Pythagorean doctrine. Caesar wrote that druids taught the immortality of the soul, believing it moved to a new body after death. This belief, he said, helped people face death bravely.
Diodorus Siculus, writing in 36 BCE, also described druids following the Pythagorean belief in the soul's immortality and reincarnation. Caesar noted that druids taught the god "Dispater," meaning "Father Dis," as the ancestor of their tribe. Diogenes Laertius wrote that druids used riddles and warnings to teach people to worship gods, avoid evil, and act bravely.
Druids in mythology
Druids are important figures in Irish stories, often serving as priests and advisors to kings and lords. They are known for their ability to predict the future and perform other special powers. 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 ability to predict the future. In the tale of Deirdre of the Sorrows, a key character in 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 because of her. The king ignored this warning, and the prophecy came true.
Another important druid was Amergin Glúingel, a bard and judge for the Milesians in the Mythological Cycle. The Milesians tried to take over the land of Ireland from the Tuatha Dé Danann. As the Milesians approached, the druids of the Tuatha Dé Danann created a magical storm to stop their ships from landing. Amergin then called upon the spirit of Ireland itself, chanting powerful words 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 mythology include Tadg mac Nuadat, who appears in the Fenian Cycle, and Mug Ruith, a blind druid with great power from Munster.
Female druids
Irish mythology includes many female druids who held important roles in culture and religion, similar to their male counterparts. The Irish language has several names for female druids, such as "bandruí," meaning "woman-druid." These figures appear in ancient stories, like "Táin Bó Cúailnge," where "bandruí" is mentioned. Another is "Bodhmall," a character from the Fenian Cycle and a caretaker of Fionn mac Cumhaill during his childhood. "Tlachtga" is the daughter of the druid Mug Ruith and is linked to the Hill of Ward, a place where festivals were held in her honor during the Middle Ages.
"Biróg," a "bandruí" from the Tuatha Dé Danann, plays a major role in a folktale. In this story, the Fomorian warrior Balor tries to stop a prophecy that he will 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 tale from the "Metrical Dindshenchas." She joins other Tuatha Dé members to defeat the 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 Scottish "bandrúi," 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 from Île de Sein, a small island near Pointe du Raz in western Brittany. These women lived on the island and were not allowed to interact with men, though they visited the mainland to meet their husbands. Their religious beliefs and the gods they honored are unknown. Pomponius Mela wrote that the Gallizenae served as advisors and healers. He described them as nine priestesses who could control the sea and wind, change into animals, cure diseases, and predict the future. They only helped travelers who came to consult them.
The "Historia Augusta" records that Alexander Severus received a prophecy about his death from a Gallic druidess. It also mentions that the Roman emperor Aurelian asked druidesses about the future of his descendants, and they predicted that Claudius II would succeed him. Flavius Vopiscus noted that the Roman emperor Diocletian received a prophecy from a druidess of the Tungri people.
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 ancient writers viewed druids to how Europeans in the 15th and 18th centuries viewed societies they encountered in places like the Americas and the South Sea Islands. He noted that both groups saw these societies as less advanced in technology and social organization.
Historian Nora Chadwick, whose ideas were later used by Piggott, divided the ancient writings about druids into two groups. The first group, called the "Posidonian" tradition after the writer Posidonius, criticized Iron Age societies in Western Europe, calling them "barbaric." The second group, called the "Alexandrian" tradition, was influenced by scholars in Alexandria, Egypt, and showed more respect for these cultures. Piggott compared this to ideas about "hard primitivism" and "soft primitivism" studied by historians Arthur Oncken Lovejoy and Franz Boas.
Some scholars believe the ancient accounts of druids are unreliable and may be fictional. They argue that the Romans and Greeks created the idea of druids to portray these societies as "barbaric" outsiders, which helped justify Roman expansion into these regions.
The first known written records about druids come from two Greek texts written around 300 BCE: a philosophical history by Sotion of Alexandria and a study of magic attributed to Aristotle. These texts are no longer available, but they were quoted in a 2nd-century CE work called Vitae by Diogenes Laërtius.
One part of Vitae mentions that some people believed philosophy began with "barbarian" groups, including the Magi of Persia, the Chaldaei of Babylon or Assyria, the Gymnosophistae of India, and the druids of the Celts and Gauls. These ideas were also mentioned by Aristotle and Sotion.
Greek and Roman writers from the 3rd century BCE sometimes referred to "barbarian philosophers," which may have been a way to describe the Gaulish druids.
The earliest 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 who conquered Gaul and Britain, Caesar described druids as people who performed religious rituals, led sacrifices, and interpreted spiritual matters. He said they were respected members of Gaulish society, along with a class called the equites (a privileged group in Rome). They also acted as judges.
Caesar wrote that druids followed a leader who ruled until his death, after which a new leader was chosen by voting or conflict. He noted that they met annually at a sacred site in the territory of the Carnutes, believed to be the center of Gaul. Caesar claimed that Britain was the center of druidic learning and that druids were not found among German tribes east of the Rhine. He also said young men trained to become druids had to memorize all their knowledge. Their main teaching was that souls do not die but move to new bodies. They studied stars, the cosmos, nature, and the gods, showing knowledge of astronomy, theology, and cosmology. Caesar described them as overseeing human sacrifices, often using criminals, and burning them in a wicker structure.
Modern historians have criticized Caesar’s account as possibly inaccurate. Some, like 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. Others, like Ronald Hutton, suggested Caesar portrayed druids as both civilized (because they were learned and pious) and barbaric (because they practiced human sacrifice), making them seem worthy of Roman rule but in need of "civilizing." Sean Dunham argued Caesar compared druids to Roman senators, and Daphne Nash believed he exaggerated the centralization of druidic leadership and its ties to Britain.
Some historians, however, believe Caesar’s description might be more accurate. Norman J. DeWitt suggested Caesar’s account reflected an idealized version of druidic society from the 2nd century BCE, before major conflicts like the Gallic wars of 121 BCE. John Creighton noted that druidic influence in Britain may have declined by the mid-1st century BCE due to new power structures led by chieftains. Others argue the Roman conquest itself caused the decline of druidic orders. Miranda Aldhouse-Green (2010) stated Caesar’s accounts are "our richest textual source" and "one of the most reliable," as other Roman senators would have also reported on the conquest, making it unlikely Caesar invented the druids.
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 augury. However, Caesar referred to him as "Diviciacus" and did not call 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 they were joined by poets and singers.
Archaeology
As historian Jane Webster explained, "individual druids … are unlikely to be identified archaeologically." A. P. Fitzpatrick studied symbols he thought might be related to the stars on swords from the late Iron Age. He found it hard to connect any 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 pagan society, such as the Lindow Man bog body, to Greco-Roman descriptions of sacrifices led by druids. Miranda Aldhouse-Green, a professor of archaeology at Cardiff University, noted that Suetonius’s army traveled near the Lindow Man’s site while dealing with Boudicca. She suggested the sacrifice might be connected. A 1996 discovery of a skeleton buried with advanced medical and possibly spiritual tools 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 head-band. The head-band 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. Hair traces on the metal show it was worn directly on the head without padding. The headdress looks similar to images of Romano-British priests from centuries later, leading some archaeologists to suggest 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, took control of the many tribal chiefdoms in Gaul and added the region to the Roman Republic. Historical records from later centuries describe how the new Roman rulers introduced laws to remove the druids from Gaul. According to Pliny the Elder, who wrote in the 70s CE, Emperor Tiberius (ruled 14–37 CE) passed laws that banned not only druidic practices but also other local soothsayers and healers. Pliny believed this would stop human sacrifice in Gaul. Suetonius, writing in the 2nd century CE, stated that Emperor Augustus (ruled 27 BCE–14 CE) made it illegal for someone to be both a druid and a Roman citizen. Later, Emperor Claudius (ruled 41–54 CE) passed a law that completely banned druidic religious practices.
The strongest evidence of druidic traditions in the British Isles comes from the Celtic word druwid-, which appears in Old Irish as "druídecht" (meaning "magic") and in Welsh as "dryw" (meaning "seer").
The druids, who were a priestly group, no longer existed in Wales after the Christianization of the region, which was completed by the 7th century at the latest. However, roles such as the bard and the "seer" (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, part of the westernmost settlement in the UK, St. Kilda.
Classics professor Phillip Freeman noted that the Historia Augusta, a 4th-century CE collection of imperial biographies, mentions "dryades" (translated as "druidesses") in three short passages about Gaulish women. These women may not have been direct descendants of the druids, but they show that some druidic roles, like prophecy, continued among native people in Roman Gaul. Female druids also appear in later Irish myths, such as the legend of Fionn mac Cumhaill, who was raised by the druid Bodhmall and another wise woman.
The story of Vortigern, as told by Nennius, describes how the British leader invited twelve druids to help him after being excommunicated by Germanus of Auxerre.
In religious texts about saints and martyrs, druids are often shown as magicians or 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. They try to stop Saint Patrick and Saint Columba by creating clouds and mist. Before the battle of Culdremne in 561 CE, a druid built a protective barrier around an army, though the exact meaning of this phrase is unclear. Irish druids may have had a unique way of cutting their hair. The word "druí" was used to describe "magus" (a wise person) in Latin texts, and Saint Columba once referred to Jesus as his druid. A story about Saint Beuno mentions that he saw "all the saints and druids" in a vision at his death.
Sulpicius Severus’ account of Saint Martin of Tours describes how Martin mistook a peasant funeral for druidic rituals. He stopped the procession by showing his cross, causing the people to freeze and spin in confusion. After realizing his mistake, Martin allowed them to continue.
In the 18th century, interest in druids grew again in England and Wales. John Aubrey (1626–1697) was the first modern writer to incorrectly link Stonehenge and other large stone structures to druids. William Stukeley (1687–1765) later popularized this idea. John Toland (1670–1722) is often wrongly credited with founding 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 writings. Blake’s mystical ideas were influenced by other sources, not druids. Toland was inspired by Aubrey’s theories about Stonehenge and wrote his own book about the monument. In 10th-century Wales, the roles of bards were established by Hywel Dda, and the idea that druids were their predecessors arose in the 18th century.
The 19th-century belief, based on uncritical reading of the Gallic Wars, that druids were the main resistance group in Gaul against Rome was examined and rejected before World War II. However, this idea still appears in folk history.
Druids became widely known in popular culture during the Romantic era. In Chateaubriand’s novel Les Martyrs (1809), a druid priestess falls in love with a Roman soldier. Though the story focuses on Christianity’s triumph over paganism, it helped keep the druid theme alive. In 1817, an opera called La Sacerdotessa d'Irminsul ("The Priestess of Irminsul") by Giovanni Pacini featured a druid priestess. Vincenzo Bellini’s opera Norma was initially a failure but later became popular in London. The story of Norma was similar to Medea, with the moon goddess addressed in the famous aria.
A key figure in the 19th-century Neo-druid revival was Welshman Edward Williams, known as Iolo Morganwg. His writings, published after his death, are not considered reliable by modern scholars. Williams claimed he collected ancient knowledge from a group called the "Gorsedd of Bards of the Isles of Britain." However, his works are not seen as credible sources.