Osiris in Egyptian mythology, the ruler of the underworld and judge of the dead. Osiris was credited with establishing religion and teaching his people agriculture and all the other arts of civilization. His father was Geb (Earth), his mother Nut (Sky). Isis was his sister and wife; Horus was his son. His envious brother Set, god of evil, schemed to murder Osiris. Set persuaded Osiris to lie down in a beautifully carved box, then nailed it shut and threw it in the Nile River. After a long search, Isis found the lifeless body of Osiris. Set then cut the body in 14 pieces and distributed them in various places throughout Egypt.
Isis gathered all the pieces, and with the help of Thoth reassembled the body and endowed it with life. Osiris then became ruler of the underworld and judge of the dead. A temple to Osiris was built at each spot where one of the pieces of his body was found. Horus avenged his father's death by killing Set. According to one legend, Osiris would occasionally reappear on earth in the form of a bull.
Osiris usually is pictured as a bearded man, wrapped like a mummy and wearing a miter (headdress). In one hand he is holding a grain flail, in the other a shepherd's crook. In his role as presiding judge of the underworld court passing sentence on the dead, he is pictured as having a hawk's head.