Osiris were brothers who vowed to protect their sun-god Ra. Set was known as the god of the desert and accompanied Ra during his descent to the underworld (here, Set, with Bastet protected Ra against the snake Apep). Osiris, on the other hand, was the god of fertility and the husband of .and
Out of jealousy, with Ra in favor of Osiris to rule the lower and upper Egypt (take note that Osiris’ crown/headdress is the combination of the crown for upper and lower Egypt), Set had became determined to take what he believed to be rightfully his. Staging his plot, he waited for Osiris to return. He called on some of his loyal men to make a box (like a coffin) that could fit only Osiris; Set made sure the measurements of the “box” were Osiris’. When Osiris arrived, they celebrated and feasted, and Set announced that he would give a reward to someone that would fit in the box. Several tried but they could not. Set persuade Osiris to try it on, and Osiris accepted.
As soon as Osiris was in, Set closed the box to make sure that Osiris would not escape. It was also said that Set had thrown the box with Osiris in it into the river Nile. Osiris died but eventually Isis, Osiris’ wife, performed a ritual to bring him back from the dead. She succeeded in doing so and when Set learned of this, he proceeded to kill his brother again, this time, after killing Osiris, he tore and chopped him apart and scattered his corpse all over the land.
Again, Isis succeeded in finding her husband’s remains and brought it back to life. Even though Osiris was a god, since he died, he could not live with them, as well as the mortals, thus making him an underworld god.
Osiris’ death was later avenged by Horus, son of Isis and Osiris.
It was also said that the process of embalming and mummification started on Osiris.
Such was their story.