- languages native to the majority of Europe, the Iranian plateau, and the northern Indian subcontinent
- all descended from a single prehistoric language, Proto-Indo-European, most likely spoken in the Pontic-Caspian steppe (present-day Ukraine and southern Russia)
- written evidence appeared during the Bronze Age. Mycenaean Greek, Hittite, Luwian.
- second-longest recorded history of any known language family, after Afroasiatic family
- ten major branches:
- Anatolian (extinct) - attested from 20C BCE
- Hellenic (mostly extinct, except for modern Greek and Tsakonian) - fragments from 1450 to 1350 BCE have been found; Homeric texts from 8C BCE.
- Indo-Iranian (incl Hindi-Urdu, Bengali, and Punjabi) - attested 14C BCE
- Italic (incl Latin…), including the branch of Romance languages (incl Romanian, Spanish, French, Italian, Portuguese) - attested from 7C BCE
- Celtic (incl Irish, Welsh) - attested from 6C BCE
- Germanic (incl Swedish, German, Dutch, Afrikaans, aaaaaand English) - attested from 2C
- Armenian - attested from 5C.
- Tocharian (extinct) - attested from roughly 6C, probably extinct by 10C.
- Balto-Slavic (incl Russian, Ukrainian, Polish)
- Slavic attested from 9C
- Baltic attested from 14C
- Albanian - attested from 13C