I know this may sound trivial, but in discussions about ancient ethnicities, this gets consistently confused. Namely, the difference between the self-designation of an ethnic group (endonym) and the foreign designation of the same ethnic group (exonym). Here are some modern examples of exonyms (in English) versus their respective endonyms:
Albanians | Shqiptar |
Basques | Euskaldunak |
Croats | Hvrati |
Finns | Suomalaiset |
Dutch | Nederlanders |
Germans | Deutsche |
Greeks | Ellēnes |
Hungarians | Magyarok |
Japanese | Nihonjin |
Welsh | Cymry |
The same, of course, applies for ancient ethnic groups:
Proto-Germanic tribes | Germani (Lat.), *Nemsi (Proto-Slavic) | *Θeudiskaz |
Ancient Egyptians | Aigyptoi (Gr.), Mizrahim (Hebrew) | K-M-T (*Kemet, Coptic "Kimi") |
Etruscans | Etrusci, Tusci (Lat.), Tyrsenoi (Gr.) | Rasna, Rasena |
Gauls | Celtae, Galli (Lat.), Galatoi, Keltoi (Gr.), *Walhaz (Proto-Germanic) | *Keltī, *Wolkī |
Picts | Picti (Lat.), Cruithne (Irish), Pryden (Old Welsh) | ? |
This is, of course, far from exhaustive. But, if you didn't know this before, remember this next time you talk about ancient ethnic group...