Ukko
Ukko is the supreme sky god of pre-Christian Finnish religion, ruler of thunder, rain, and harvest. He strikes his hammer Ukonvasara to create lightning; his cult centered on spring festivals (Ukon vakat) with communal drinking and offerings. In the Kalevala he appears as father of Väinämöinen and judge of Marjatta's son. Documented by Agricola (1551), Ganander, and in runic songs.