The Germanic tribes originally inhabited southern Scandinavia, Schleswig-Holstein and Hamburg, but subsequent Iron Age cultures of the same region, like Wessenstedt (800–600 BCE) and Jastorf, may also have belonged to this grouping. The climate deteriorating in Scandinavia around 850 BCE to 760 BCE and later and faster around 650 BCE might have triggered migrations. Archaeological evidence suggests around 750 BCE a relatively uniform Germanic people from the Netherlands to the Vistula and southern Scandinavia. In the west, the newcomers settled the coastal floodplains for the first time, since in adjacent higher grounds the population had increased and the soil had become exhausted. By the time this migration was complete, around 250 BCE, a few general cultural and linguistic groupings had emerged.

One grouping – labelled the "North Sea Germanic" – inhabited the northern part of the Netherlands (north of the great rivers) and extending along the North Sea and into Jutland. This group is also sometimes referred to as the "Ingvaeones". Included in this group are the peoples who would later develop into, among others, the early Frisians and the early Saxons.

A second grouping, which scholars subsequently dubbed the "Weser-Rhine Germanic" (or "Rhine-Weser Germanic"), extended along the middle Rhine and Weser and inhabited the southern part of the Netherlands (south of the great rivers). This group, also sometimes referred to as the "Istvaeones", consisted of tribes that would eventually develop into the Salian Franks.