Osiris, Isis, Set, and Nephthys were born of Geb , the sky deity and Nut the soil goddess.
Because Osiris was the oldest, he became King of Egypt, and he married his sister Isis. Osiris was a noble monarch who commanded the respect of those who lived on Earth as well as the gods who resided in the netherworld.
Set, on the other hand, was constantly envious of Osiris since he did not command the respect of those on Earth or in the Netherworld . Set turned himself into a ferocious beast and attacked Osiris killing him.
What was the relationship of osiris to isis (Osiris Horus and Isis)
Set then cut Osiris into pieces and scattered them over Egypt’s length and breadth. With Osiris’s death, Set ascended to the throne of Egypt with his sister Nephthys as his consort . Nephthys, on the other hand, felt sad for her sister Isis,
who grieved incessantly for her late husband. Isis, who possessed incredible magical abilities, resolved to find her husband and bring him back to life for long enough for them to have a child. Isis and Nephthys traversed the nation, gathering and reassembling the fragments of her husband’s body. After she finished her deed, she infused life into his body and revived him. They were back together, and Isis soon fell pregnant. Osiris was able to descend into the underworld and become master of that kingdom.

Competition for the state anointing
Horus the hawk-god was the name given to Isis’ kid. When Horus reached adulthood, he resolved to argue before the gods that he not Set , was the true monarch of Egypt. Following a lengthy debate, Set challenged Horus to a contest. The victor would be crowned king. Set, on the other hand, did not play fairly. After numerous matches in which Set cheated and won, Horus’ mother, Isis, resolved to assist her son by laying a trap for Set.
She ensnared him, but Set begged for his life, and Isis relented and let him go. Horus felt enraged with his mother after learning that she had let his adversary survive, earning him the scorn of the other gods. They agreed that there would be one more match, and Set would get to select which one.
Set determined that the contest’s final round would be a boat race. However, in order to make the match more difficult, Set and Horus agreed to race stone boats. Horus was cunning, and he created a boat out of wood that was coated with limestone plaster to make it appear like stone. Put chopped the top of a mountain to use as his boat and set it in the water as the gods gathered for the race. King of Egypt,
His boat immediately sank, and all the other gods laughed at him. The set became enraged and changed. He transformed himself into a hippopotamus and attacked Horus’ boat. Horus fought Set, but the other gods intervened before he could slay him. The contest was declared a draw by the other gods. Many of the gods sympathized with Horus but recalled his wrath toward his mother for being merciful to Set and were hesitant to fully back him.
The gods that comprised the court agreed to write a letter to Osiris and seek his counsel. Osiris gave a firm response: his son is the true monarch and should be installed on the throne.
No one, Osiris declared, should gain the throne of Egypt via murder, as Set had done. The set had slain Osiris, while Horus had not killed anybody and was thus the superior option. The sun and stars, Osiris’ friends, descended into the underworld, leaving the earth in darkness. Finally, the gods decided that Horus should take his rightful place as King of Egypt. (Osiris Horus and Isis)