Perkūnas (Perkūnas, Pērkons, Old Prussian: Perkūns, Perkunos, Yotvingian: Parkuns, Latgalian: Pārkiuņs) was the common Baltic god of thunder, and the second most important deity in the Baltic pantheon after Dievas. In both Lithuanian and Latvian mythology, he is documented as the god of sky, thunder, lightning, storms, rain, fire, war, law, order, fertility, mountains, and oak trees.
Perkwunos
The name continues PIE *, cognate to *, a word for "oak", "fir" or "wooded mountain". The Proto-Baltic name *Perkūnas can be reconstructed with certainty. Slavic Perun is a related god, but not an etymologically precise match. Finnish Perkele, a name of Ukko, is considered a loan from Baltic.
Another connection is that of terpikeraunos, an epithet of Zeus meaning "who enjoys lightning".
Most information about Perkūnas comes from folklore songs, legends, and fairy tales. Because most of them were collected rather late in the 19th century, they represent only some fragments of the whole mythology. Lithuanian Perkūnas has many alternative onomatopoeic names, like Dundulis, Dindutis, Dūdų senis, Tarškulis, Tarškutis, Blizgulis, etc.
The earliest attestation of Perkūnas seems to be in the Russian translation of the Chronicle of John Malalas (1261) where it speaks about the worship of "Перкоунови рекше громоу", and in the Livonian Rhymed Chronicle (around 1290) which mentions the idol Perkūnė.
In the Constitutiones Synodales (1530) Perkūnas is mentioned in a list of gods before the god of hell Pikuls and is identified with the Roman Jove (Jupiter). In the Sudovian Book Perkūnas (Parkuns) is mentioned in connection with a ritual involving a goat. In Christian compositions, Perkūnas is a malicious spirit, a demon, as in the Chronicle of John Malalas or in the 15th century writings of Polish chronicler Jan Długosz.
Perkūnas is the god of lightning and thunder and storms. In a triad of gods Perkūnas symbolizes the creative forces (including vegetative), courage, success, the top of the world, the sky, rain, thunder, heavenly fire (lightning) and celestial elements, while Potrimpo is involved with the seas, ground, crops, and cereals and Velnias/Patulas, with hell, and death.