Perkūnas (, , 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.
Etymology
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".
Perkūnas in written sources
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 Ruthenian 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.
Representation in mythology
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. As a heavenly (atmospheric) deity Perkūnas, apparently, is the assistant and executor of Dievas‘s will. However, Perkūnas tends to surpass Dievas, deus otiosus, because he can be actually seen and has defined mythological functions.
In the Latvian dainas, the functions of Pērkons and Dievs can occasionally merge: Pērkons is called Pērkona tēvs ('Father or God of Thunder') or Dieviņš, a diminutive form of Dievs.
Weapons and vehicle
Perkūnas is pictured as middle-aged, armed with an axe and arrows, riding a two-wheeled chariot harnessed with goats, like Thor or Celtic Taranis.
In other accounts, the thunder god is described as driving a fiery chariot through the skies with swift horses, or riding a fiery horse.
Perkūnas' family relations
In songs about a "heavenly wedding" Saulė (the Sun) cheats on Perkūnas with Mėnulis (the Moon); Perkūnas splits Mėnulis in half with a sword. According to another, more popular, version, Mėnulis cheats on the Sun with Aušrinė (the morning star) just after the wedding, and Perkūnas punishes it. However, it does not learn and repeats the adultery and is punished again every month. Other explanations say it is why the Sun shines during the day and the Moon at night. Though divorced, both want to see their daughter Žemyna (the Earth).
In other songs Perkūnas, on the way to the wedding of Aušra (dawn; the daughter of the Sun), strikes a golden oak. The oak is a tree of the thunder god in the Baltic mythology. Lithuanian Perkūno ąžuolas or Latvian Pērkona ozols ("oak of Perkūnas") is mentioned in a source dated to the first half of the 19th century.
Other myths say that Perkūnas and one Laumė or Vaiva (rainbow) were supposed to get married on Thursday, but the bride was kidnapped by Velnias (the devil) and Perkūnas has hunted Velnias ever since.
Some myths mention four sons of Perkūnas (Latvian: Perkona dēli; Lithuanian: Perkūno sūnūs), who, apparently, are connected with the four seasons or with the four directions of the world (east, west, south and north). Sometimes there are seven or nine Perkūnai referred to as brothers. It is said in Lithuanian "Perkūnų yra daug" ("there are many thunders").