Wikipedia
Belobog
Belobog, Bilobog, Belbog, Bialbog, Byelobog, Bielobog, Belun or Bylun (all names meaning White God) is a reconstructed Slavic deity of light and Sun, the counterpart of dark and cursed Chernobog (Black God). It is uncertain whether such a deity was ever worshipped by polytheist Slavs, as there are no reliable historic records which mention this name. While in the past a great deal of scholars studying Slavic mythology took the dualism of Belobog and Czernobog for granted, modern research of the matter makes this theory very hard to maintain.