This essay deals with Celtic ethnography of Southern Gaul as described by Posidonius of Apamea (135-50 B.C.), one of the most important and influential scientist and philosopher in the Hellenistic world, a polymath who travelled a lot in Celtic lands from 101 B.C. to 91 B.C., supported by Roman aristocracy. It is a Greek intellectual's sharp point of view about the description of Celtic customs and many interesting cultural and social aspects as feasts, duels, tribe economy, forms of servile people employed by chiefs, anthropological analysis of Celtic character, weapons and war behaviour, religion and customs of Druids. He was an invaluable direct eye-witness of that world, but we have only indirect fragments of Posidonius' books (what we know comes above all from Athenaeus, Diodorus and Strabo) and by them it is possible to gather that Posidonius is an original heir of many previous ethnographical topoi, and moreover he is a witness of free Celtic world, who uses Stoicism's eyes to explain some aspects of that alien reality and he thinks that contemporary Celts are very similar to ancient Greeks of Homeric poems, so barbarian people of Gaule is described as heroes of Greek epos, using Homeric words and expressions.
Posidonius, even though carrying out research into Celtic ethnography, compares Celtic customs to behaviour of heroes of Greek epic tradition. Anyway if we read Posidonius' descriptions we can find a deep analogy with various aspects of Celtic society of sagas of Gaelic Middle-Age tradition, particularly of some famous Irish sagas: first of all Fled Bricrenn and then Scéla Muicce Meic Da Thó. This comparison between legendary stories written in XII century in Ireland and the descriptions of Greek writer shows that Posidonius was a trustworthy writer in his ethnographical report of the Celts. In many cases this correspondance about Celtic world is really astonishing. In conclusion, Celtic archaeology -archaeological finds as weapons, pots, funeral ornaments and jewels- (insular and continental) confirmed Posidonius' reliability about ancient Celts, too. It is a very good reason to increase what Posidonius, clear Greek traveller before Caesar's De Bello Gallico, wrote about Celts and Cimbri, northern people of Europe that Romans defeated in 101 B.C. in the battle of Campi Raudii.
15th International Congress of Celtic Studies 13-17 July 2015, University of Glasgow.