This is the story for the costume
Somewhere under the sun, reigned one pharaoh. He was a good and fair. All considered him the wisest man in these lands. He had two small sons - Shams(Sun), firstborn and Yamar(Moon). When the time came for one of them to become pharaoh, the old father called one by one his sons, and to each said that the other would become pharaoh (He wanted to test them).
Yamar no major claims and accepted, but Shams, who was convinced that will be the new pharaoh offended too much. His anger increased so the same night he killed his brother.