Voices of Antiquity: Volume 1: Posidonius

The Lost Voice Behind the Ancient Druids

“Although none of his writings survive, few ancient authors have had a greater influence on our understanding of the ancient Druids than Posidonius of Apamea. Through the works of later writers, fragments of his observations continue to echo across more than two thousand years of history.”

Name: Posidonius of Apamea
Dates: c. 135–51 BCE
Occupation: Greek philosopher, historian, geographer, scientist, and traveler
School: Stoicism
Principal Work: Histories (now lost)
Relationship to the Druids: Traveled through Gaul and recorded observations of Celtic society.
Importance: Although his writings have not survived, Posidonius profoundly influenced later authors, including Diodorus Siculus and Strabo, and may have shaped the wider Greek and Roman understanding of the Druids.

Who Was Posidonius?

Long before Julius Caesar began his conquest of Gaul, the Greek philosopher Posidonius traveled through parts of the Celtic world and recorded observations of the peoples he encountered. Born around 135 BCE in Apamea, in present-day Syria, Posidonius became one of the most respected intellectuals of the Hellenistic world. A Stoic philosopher by training, he was equally interested in history, geography, astronomy, ethnography, and the customs of the peoples he encountered. His curiosity led him to travel widely throughout the Mediterranean and western Europe, including parts of Gaul.

Unlike many writers who relied solely upon secondhand reports, Posidonius appears to have observed aspects of Celtic society firsthand. Although the precise extent of his travels remains debated, ancient authors consistently regarded him as an important authority on the peoples of western Europe.

One of the greatest frustrations for historians is that Posidonius’ writings have not survived. His great historical work, commonly known simply as the Histories, has been lost. What we know of his observations comes almost entirely through later authors who quoted, summarized, or adapted his work. The clearest examples are Diodorus Siculus and Strabo, both of whom preserve material that scholars widely believe derives, at least in part, from Posidonius. Other authors, such as Athenaeus, also quote him directly on Celtic customs. Whether Julius Caesar was influenced by Posidonius remains a matter of scholarly debate, though both belong to the broader Greek and Roman ethnographic tradition describing the peoples of Gaul.

Because these authors often preserve similar descriptions of the Druids, Bards, and Vates, historians believe they were drawing, at least in part, upon Posidonius. This means that although we cannot read Posidonius directly, his voice still echoes through much of the surviving ancient literature concerning the Celtic peoples.

What Did Posidonius Describe?

Although his original work has been lost, several themes consistently appear in passages attributed to him or believed to derive from his observations.

These include:

• The Druids as philosophers and religious specialists.
• The Bards as poets and singers.
• The Vates as seers and ritual practitioners.
• Human sacrifice.
• Head-taking and the display of enemy heads.
• Celtic warfare.
• Feasting and hospitality.
• Religious customs.
• The social organization of Celtic communities.

Many of these themes reappear in the writings of Diodorus Siculus and Strabo, suggesting that they were drawing upon a common source. Studying Posidonius requires a different approach than studying most ancient authors. Because his original work has been lost, historians cannot simply quote him directly. Instead, they compare the surviving passages preserved by later writers, examine where those accounts agree and differ, and consider how faithfully each author may have transmitted his observations.

Posidonius occupies a unique place within the study of the Druids. He is both absent and ever-present. Sadly, we will never know the full extent of Posidonius’ writings or how many observations of the Druids and the Gaulish peoples have been lost with his Histories.

Continue the series

Voices of Antiquity: Volume 1: Cicero: A Roman statesman who personally knew the Druid Diviciacus.