Helios was one of the ancient Greek sun gods, the other was Apollo. Helios rode a chariot through the sky every day and his horses breathed fire. Many Bronze Age and Iron Age people believed the sun rode in a chariot. There is a famous statue of Helios in his chariot on the Brandenburg gate in Berlin.  The Romans called helios Sol  and on December 24th they celebrated a festival called Sol Invictus meaning the Unconquered Sun. Christians took that ceremony over and called it Christmas. 
In The Odyssey, Helios warned the great Odysseus not to eat the sheep. However, after Odysseus left camp, his men ignored this warning and killed several sheep to eat. Helios then killed many of Odysseus' men as punishment for suckling on the sweet meat of his golden sheep.
Now all that's marvellous and that's typical of Mythology.
Adapted from a deleted RationalWiki article
- Above us Only SkyThis gives the history of what people used to believe about the sun.