necessarily etymologically related to , but always associated with thunder. For example, the Vedic and (the personification of drought), the Iranian /Sirius and (a demon of drought), the Albanian and (an amphibious serpent who causes streams to dry up), the Armenian and , the Greek Zeus and Typhoeus as well as Apollo and Python, or the Norse Thor and . Striker and god of oaks The association of with the oak is attested in various formulaic expressions from the Balto-Slavic languages: Lithuanian (Perkūnas's oak), Latvian ('Pērkōn's oak'), or Old Russian ('Perun's oak'). In the Albanian language, a word to refer to the lightning—considered in folk beliefs as the "fire of the sky"—is shkreptimë, a formation of shkrep meaning "to flash, tone, to strike (till sparks fly off)". An association between strike, stones and fire, can be related to the observation that one can kindle fire by striking stones against each other. The act of producing fire through a strike—reflected also in the belief that fire is residual within the oak trees after the thunder-god strikes them—indicates the potential of lightning in the myth of creation. The Slavic thunder-god Perūn is said to frequently strike oaks to put fire within them, and the Norse thunder-god Thor to strike his foes the giants when they hide under an oak. According to the Belarusian folklore, Piarun made the first fire ever by striking a tree in which the Demon was hiding. The striking of devils, demons or evildoers by is another motif in the myths surrounding the Baltic Perkūnas and the Vedic Parjanya. In Lithuanian and Latvian folkloric material, / is invoked to protect against snakes and illness. Wooded mountains is often portrayed in connection with stone and (wooded) mountains; mountainous forests were considered to be his realm. A cognate relationship has been noted between the Germanic ('[mountainous] forest') and the Gaulish ('[oaks] forests'). The Old Russian chronicles describe wooden idols of Perūn on hills overlooking Kyiv and Novgorod, and both the Belarusian Piarun and the Lithuanian Perkūnas were said to dwell on lofty mountaintops. Such places are called in Lithuanian, meaning the "summit of Perkūnas", while the Slavic word designated the hill over Novgorod where the sanctuary of was located. Prince Vladimir the Great had an idol of cast down into the Dnepr river during the Christianization of Kievan Rus'. In Germanic mythology, Fjörgynn was used as a poetic synonym for 'the