Classical references and toponomastics suggest that the Ligurian sphere once extended further into central Italy (Taurisci): according to Hesiod's Catalogues (early 6th century BC) they were one of the three main "barbarian" peoples ruling over the Western border of the known world (the others being Aethiopians and Scythians). Avienus, in a translation of a voyage account probably from Marseille (4th century BC) speaks of the Ligurian hegemony extending up to the North Sea, before they were pushed back by the Celts. Ligurian toponyms have been found in Sicily, the Rhône valley, Corsica and Sardinia.
It is not known for certain whether they were a pre-Indo-European people akin to Iberians; a separate Indo-European branch with Italic and Celtic affinities; or even a branch of the Celts or Italics. Kinship between the Ligures and Lepontii has also been proposed. Another theory traces their origin to Betica (modern Andalusia).