ルウィ語
According to the widely held Kurgan hypothesis, c.q. renewed Steppe hypothesis, the oldest branch were the Anatolian languages (Hittite language and Luwian language) which split from the earliest proto-Indo-European speech community (archaic PIE), which itself developed in the Volga basin. The second-oldest branch, the Tocharian languages, were spoken in the Tarim Basin (present-day western China), and split-off from early PIE, which was spoken on the eastern Pontic steppe. The bulk of the Indo-European languages developed from late PIE, which was spoken at the Yamnaya horizon in the Pontic–Caspian steppe, around 3000 BCE.