Ra, the Sun god, was seen as a self-created god. He came out from a lotus on the Primevial Ocean (Noun) at the first morning. He gave Life to all other gods and creatures. So he was seen as dispensiator of life.
He was first mainly worshipped at Iounou/Heliopolis and became a royal protector (since 2600 BC, the King is called Son of Re). Unfortunately, Ra's importance is better known by later sources (f.eg. Middle or New Kingdom)
For more details, see Stephen QUIRKE. 2001. The Cult of Ra. Sun-worship in Ancient Egypt. London