It is assumed that its introduction to the Iberian peninsula followed the third century expansion of German speaking people to south Holland and across the lower Rhine into what is now Belgium.

Hallstatt cultural assemblies are present in Iberia west of a line from the eastern Pyrenees to the Algarve. These may have been introduced by Q-Celtic speakers whose language, strongly influenced by contact with Iberian, perhaps on the upper Ebro, became Celtiberian.