Osiris was an Egyptian god, usually identified as the god of the afterlife, the underworld, and the dead, but more appropriately as the god of transition, resurrection, and regeneration. Osiris was considered not only a merciful judge of the dead in the afterlife, but also the underworld agency that granted all life, including sprouting vegetation and the fertile flooding of the Nile River.
He was classically depicted as a green-skinned man with a pharaoh's beard, partially mummy-wrapped at the legs, wearing a distinctive crown with two large ostrich feathers at either side, and holding a symbolic crook and flail.
Osiris was at times considered the oldest son of the earth god Geb, though other sources state his father is the sun-god Ra and the sky goddess Nut, as well as being brother and husband of Isis, with Horus being considered his posthumously begotten son. Being the father of Horus, whose conception is described in the Osiris myth, is a central myth in ancient Egyptian belief. 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 reproductive organ.
Isis fashioned a golden reproductive organ, 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. Isis later gave birth to Horus. As such, since Horus was born after Osiris' resurrection, Horus became thought of as a representation of new beginnings and the vanquisher of the evil Set.