[1] The language was introduced to Anatolia in the 3rd century BC, when Celtic tribes – notably the Tectosages, Trocmii, and Tolistobogii – migrated south from the Balkans.

Sometime in AD 48–55, the Apostle Paul wrote his Epistle to the Galatians in Greek, the medium of communication in the eastern parts of the Roman Empire.

[5][6] Lucian of Samosata recorded in circa AD 180 that the prophet Alexander of Abonoteichus was able to find Celtic-speaking interpreters for his oracles in Paphlagonia (immediately northeast of Galatia).

[7][8] The physician Galen of Pergamon in the late 2nd century AD complained that the commonly spoken Greek of his day was being corrupted by borrowings of foreign words from languages such as Galatian.

Scattered vocabulary terms mentioned by Greek authors include ἀδάρκα (adarka), a type of plant; αδες (ades), "feet"; βαρδοί (bardoi), "singing poets, bards"; μάρκα (marka), "horse" and τριμαρκισία (trimarkisia), "three-horse battle group".

[1] Both taskos and droungos are given by Epiphanius of Salamis in his Panarion in an effort to elucidate the name of the gnostic sect of the Tascodrugites.

the related Volcae Tectosages tribe of Gaul, "Travel-seekers"; Old Irish techt, "going, proceeding", Welsh taith, "journey, voyage").