Why did the ancient Greeks and Persians fear the Celtic nations?
Although we normally associate the Celts with western Europe, especially with the British Isles, from the early iron age (ca 700 BC) Celtic speaking peoples ranged far more widely in Europe including what is now Germany, Eastern Europe, Italy and Iberia. Groups of Celts also journeyed into Greece and Macedonia. Celts were renowned as fierce warriors and fought as mercenaries in Greek armies. It is thus not unreasonable for them to achieve a fearsome reputation not only with the Greeks but also with the Persians — long time rivals of the Greeks. Further, in 279 BC, Celts invaded Greece, pillaging Thrace and Macedonia and killing a Macedonian king. They even settled in Asia Minor (modern day Turkey) — land that bordered both Greek and Persian territory — until a Greek army defeated them in 230 BC.
