Caucones
According to brief mentions by Herodotus and some other classical writers, the Caucones (or Kaukones) were an indigenous ("autochthonous") tribe of Anatolia who were displaced or absorbed by the immigant Bithynians, who were a group of clans from Thrace that spoke an Indo-European language. In Anatolia (moder-day Turkey) the Thracian Bithynians expelled or subdued the Mysians, Caucones, and other minor tribes, the Mariandyni alone maintaining themselves in cultural independence in the northeast of what became Bithynia.What kind of pre-Indo-European language the illiterate Caucones spoke is a ludibrium of opposing camps of modern-day linguists, who tend to allign themselves according to their modern ethnicities.
In Greece itself, the Hellenes tended to lump all pre-Hellenic indigenes together as "Pelasgians".