Amun is a god from the new kingdom and Ra is the god of the sun, causing people to merge them together to create Amun-Ra, King of the Gods. (Some of this mighht not be accurate, just kinda an explanation from the top of my head)
Amun Ra's original name was Amun, or Amen, or Amon. Amun Ra is the name given to him when he gained national importance. Amun and Ra was different in mythology, until the people merged those two deities together. Something like that, I think.
Comments on Profile Post by Untitled Doc