With the discussion of the religion of the Celts in Antiquity we come to the end of our review of the complex relationship over many centuries between the civilisation of the Mediterranean basin and the great aggregate of Celtic peoples which stretched across Europe and which, from the fourth century BC onwards, began to decline in power. In the centuries through which our discussion has ranged, there was scarcely any time when the Celts were not in some place seen as a menace, real or imagined, to the Mediterranean way of life represented by the Greek city-states and Rome with her allies and provinces. The intelligence and vigour of the Celts made them close in potential to the more settled societies of Greece and Rome. It was their primary physical energy in battle and their devotion to raiding that posed a special threat to the Classical world.
When the Celts invaded Greece in 278 BC, the likelihood is that Greece would have been wrecked, but not destroyed, by a Celtic victory. Greece was difficult in terrain and essentially out of range of Celtic capacities to overrun and colonise it. The Galatians of Asia Minor founded a powerful and lasting nation in the lands into which they were eventually thrust by the Hellenistic kingdoms, but their impact on the history of this sizeable continent was disproportionately small. A lateral federation of tribes made it difficult here, as elsewhere, for strong leadership to develop which could give effect to national policies. Consequently these Celts were used by others for the furtherance of alien policies.
The Celtic armies made a greater impact on Italy, part of which they made into a Celtic country. They helped to destroy, but could not replace, the advanced civilisation of Etruria. It was the misfortune of the Celts that they came into contact with Rome at a time