In Slavic mythology, Perun (Cyrillic: Перýн) is the highest god of the pantheon and the god of sky, thunder, lightning, storms, rain, law, war, fertility and oak trees. His other attributes were fire, mountains, wind, iris, eagle, firmament (in Indo-European languages, this was joined with the notion of the sky of stone), horses and carts, weapons (hammer, axe (Axe of Perun), and arrow), and war. He was first associated with weapons made of stone and later with those of metal.
Of all historic records describing Slavic gods, those mentioning Perun are the most numerous. As early as the 6th century, he was mentioned in De Bello Gothico, a historical source written by the Eastern Roman historian Procopius. A short note describing beliefs of a certain South Slavic tribe states they acknowledge that one god, creator of lightning, is the only lord of all: to him do they sacrifice an ox and all sacrificial animals. While the name of the god is not mentioned here explicitly, 20th century research has established beyond doubt that the god of thunder and lightning in Slavic mythology is Perun. To this day the word perun in a number of Slavic languages means “thunder,” or “lightning bolt”.