Does anyone know was it long distance trade? or more short hand to hand to hand hop style trading?
Really amazing what a world must of existed at some point in the anceint world that we have little understanding or knowledge of.
From what I have studied about this the primary spread and exchange was by sea, from Scandinavia through the Mediterranean and to the Black Sea.
When Caesar was conquering Gaul, he wound up deciding to make his two expeditions to Britain because his mainland adversaries were fleeing in their ships to the island. Celtic populations didn't get to Britain on foot, nor had those who'd been there when they arrived.