Ukko

Attestation

Mikael Agricola's list of 1551 includes Ukko, and describes a spring rite: when the sowing was done, Ukko's bowl (Ukon malja) was drunk, and Agricola complains of the drunkenness and shameful conduct that went with it. Folk poetry calls him ylijumala, the highest god, and addresses him in charms and prayers for rain and against storms; a thunderstorm is still ukonilma, 'Ukko's weather', in Finnish. Neolithic stone axes turned up by the plough were called ukonvaaja or ukonkirves, 'Ukko's wedge' or 'axe', and were believed to be thunderbolts he had hurled.

In the Kalevala

Ukko appears as the supreme power to whom the characters pray. In the first rune the air-maiden Ilmatar, adrift and in labor on the primeval sea, calls on him: 'Ukko, thou O God, up yonder, / Thou the ruler of the heavens'. Heroes invoke him for help with bow, boat, and battle, and when Louhi hides the sun and moon, Ukko strikes fire to make a new light.

An older thunder god

The Finnish word perkele, now a notorious curse meaning 'devil', is an old borrowing of the Baltic thunder god's name (Lithuanian Perkūnas), suggesting that Finnic peoples once knew a thunder god under that name before Christianity demonized it. Some later sources give Ukko a consort, called Akka or Rauni, but the evidence for her is thin.