By the late third millennium BC , offshoots of the Proto-Indo-Europeans had reached Anatolia ( Hittites ) , the Aegean ( Mycenaean Greece ) , Western Europe ( Corded Ware culture ) , the edges of Central Asia ( Yamna culture ) , and southern Siberia ( Afanasevo culture ) .
By the mid-2nd millennium BC offshoots of the Proto-Indo-Europeans had reached Anatolia , the Aegean , Northern India , and likely Western Europe .