Peoples on the move
The movement of Celts from north of the Alps into the Mediterranean lands in the period from about 400 BC is amply documented by Greek and Roman historians writing several centuries after the events. The sources are sufficiently detailed to provide an outline history of the various migrations and raids and to offer some insight into the nature of the communities involved and the fighting methods of the warriors. That said, it must be remembered that our two principal sources, Polybius (c.204–122 BC) and Livy (59 BC–ad 17), were writing to specific pro-Roman agendas and readily adopted, and indeed embellished, the established Celtic stereotype. Nevertheless, they will have had access to sources no longer available and the basic history of what they have to offer can be broadly accepted.
Livy gives a simple sketch of how the migrations began. They originated in Gaul under the leadership of the Bituriges and were sparked off by overpopulation. The king, Ambigatus, chose his two nephews to lead the exodus, and, after consulting the augurs, one led his people eastwards through the Black Forest and Bohemia, while the other moved south into Italy. ‘Taking with him the surplus populations – Bituriges, Arverni, Senones, Aedui, Ambarri, Carnutes, Aulerci – he set out with a vast host, some mounted, some on foot’ (Hist. 5.34). Once through the Alps they established a settlement at Mediolanum (now Milan). A later writer, Pompeius