Sius is the Hittite sun god. Siu while in two sub-branches we find the Sun as Tiwat (Luwian) and Tivaz (Palaic). In Greece, this appears as Zeus/Dia, the Thunderer, King of gods on Olympus. The Romans had Jūpiter (< Jus-/Jup-pitar = Gk Zeus-patēr). Among the Gmc people the Skyfather appeared early as Tiwaz much as in Luwian and Palaic. See that Lth dievas is usually ‘god’ and only in some Ltt songs means ‘skygod’. The name appears as Divŭ among the south-eastern Russians, a watching, protecting god. Cited from Website: Diffusion