The Indo-European Thunderer

Perkunas is one of the clearest witnesses to a reconstructed Indo-European storm-god. His name is traced to a root *Perk(w)unos, and comparative philologists set him beside the Slavic Perun, the Vedic Parjanya, and, by function if not by name, Norse Thor and Vedic Indra. Recurring across these figures are the oak, the axe or hammer, the thunderbolt, and above all the myth in which the thunderer strikes a serpentine adversary of the low and watery world, in the Baltic material, Perkunas hunting and smiting Velnias.

Some scholars (notably Ivanov and Toporov) built an elaborate "basic myth" of the storm-god versus his chthonic enemy on exactly this pattern. The comparison is illuminating but is also a caution: the neatness of the reconstruction partly reflects the scholars' expectation of finding an Indo-European storm-god, and the folk songs are richer and stranger than the tidy combat-myth allows.