...t forth to Thermopylae with such Greeks as joined them, having made the Callippus I mentioned their general. Occupying the pass where it was narrowest, they tried to keep the foreigners from entering Greece ; but the Celts, having discovered the path by which Ephialtes of Trachis once led the Persians, over whelmed the Phocians stationed there and crossed Oeta unperceived by the Greeks.