Proto-Indo-Europeans
The Proto-Indo-Europeans were a patrilineal society, probably half-nomadic, relying on animal husbandry, notably of cattle and sheep. They domesticated the horse – ekwos (cf. Latin equus).  The cow (gwous) played a central role, in religion and mythology as well as in daily life. A man's wealth would have been measured by the number of his animals (small livestock), peḱus (cf. English fee, Latin pecunia).