Svarog and Dažbog

In the Hypathian Codex, there is a tale which was translated from the
language of the Byzantines. It tells us a story about the Egyptian God of
the sky and his child, the Sun. The Byzantines referred to the God of the
Sky as Hephaestus, and to the God of the Sun as Helios. Later, when this
text was translated into Slavonic, the names were changed to Svarog as the
God of the Sky and Dazhbog, as the God of the Sun:

(Then) began his reign Feosta (Hephaestus), whom the Egyptians called
Svarog <…> during his rule, from the heavens fell the smith’s prongs and
weapons were forged for the first time; before that, (people) fought with
clubs and stones. Feosta also commanded the women that they should have
only a single husband… and that is why Egyptians called him Svarog <…>
After him ruled his son, his name was the Sun, and they called him Dažbog
<…> Sun tzar, son of Svarog, this is Dažbog.

Hypathian Codex, translation of John Malalas’ Chronicle 

-Daelendil