Osiris is killed in several Egyptian myths, coming back to life for varying lengths of time in some of them.
The myth described Osiris as having been killed by his brother Set, who wanted Osiris' throne. Isis joined the fragmented pieces of Osiris, but the only body part missing was the phallus. Isis fashioned a golden phallus, and briefly brought Osiris back to life by use of a spell that she learned from her father. This spell gave her time to become pregnant by Osiris before he again died.
Plutarch recounts one version of the myth in which Set (Osiris' brother), along with the Queen of Ethiopia, conspired with 72 accomplices to plot the assassination of Osiris. Set fooled Osiris into getting into a box, which Set then shut, sealed with lead, and threw into the Nile. Osiris' wife, Isis, searched for his remains until she finally found him embedded in a tamarisk tree trunk, which was holding up the roof of a palace in Byblos on the Phoenician coast. She managed to remove the coffin and open it, but Osiris was already dead.
In one version of the myth, she used a spell learned from her father and brought him back to life so he could impregnate her. Afterwards he died again and she hid his body in the desert. Months later, she gave birth to Horus. While she raised Horus, Set was hunting one night and came across the body of Osiris. Enraged, he tore the body into fourteen pieces and scattered them throughout the land. Isis gathered up all the parts of the body, except the penis (which had been eaten by a fish, the medjed) and bandaged them together for a proper burial. The gods were impressed by the devotion of Isis and resurrected Osiris as the god of the underworld. Because of his death and resurrection, Osiris was associated with the flooding and retreating of the Nile and thus with the crops along the Nile valley.
Diodorus Siculus gives another version of the myth in which Osiris was described as an ancient king who taught the Egyptians the arts of civilization, including agriculture, then travelled the world with his sister Isis, the satyrs, and the nine muses, before finally returning to Egypt. Osiris was then murdered by his evil brother Typhon, who was identified with Set. Typhon divided the body into twenty-six pieces, which he distributed amongst his fellow conspirators in order to implicate them in the murder. Isis and Hercules (Horus) avenged the death of Osiris and slew Typhon. Isis recovered all the parts of Osiris' body, except the phallus, and secretly buried them. She made replicas of them and distributed them to several locations, which then became centres of Osiris worship.