2009: "Recent evidence that Druids possibly committed cannibalism and ritual human sacrifice, perhaps on a massive scale, add weight to ancient Roman accounts of Druidic savagery, archaeologists say. After a first century B.C. visit to Britain, the Romans came back with horrific stories about these high-ranking priests of the Celts, who had spread throughout much of Europe over a roughly 2,000-year period. Julius Caesar, who led the first Roman landing in 55 B.C., said the native Celts "believe that the gods delight in the slaughter of prisoners and criminals, and when the supply of captives runs short, they sacrifice even the innocent." First-century historian Pliny the Elder went further, suggesting the Celts practiced ritual cannibalism, eating their enemies' flesh as a source of spiritual and physical strength."

https://www.nationalgeographic.com/culture/article/druids-sacrifice-cannibalism