Horus is the son of Osiris and Isis. Osiris and Isis succeeded Ra as rulers of Egypt and reconceived their one-time brother. Osiris was soon killed by a jealous Set and Isis was forced to flee for both her life as well as that of her unborn son.
Despite being hounded by Set and his minions, Isis gave birth to Horus and also managed to recover Osiris' body even after it was destroyed by Set. Osiris was resurrected but he was still not fully restored, leaving him unable to fully return to life. Departing for the Duat, Osiris named Horus as his heir. Despite numerous attempts by his uncle to kill him, Horus would come of age and challenge Set for the throne. He would eventually triumph after seven years of battle and thus became the main hosting god of the pharaoh.