Osiris was the progeny of a vampire known as "Typhon", who anticipated that his skills would be useful in the growing Jyhad. However, he did not accept his new condition and sought to overcome it. Thus, he invested his time in ancient methods of meditation and deep mystical enlightenment to develop a new Discipline, the Bardo. This discipline allowed one to control the ravishing beast within. After gaining mastery of it, he preached this newfound way to other Kindred, thus forming a caitiff "lineage", not necessarily a clan or bloodline, known as the Children of Osiris.
It is said that he was born of Geb and Nut, being the older brother of Set. They lived on the Nile of Egypt, under the rule of their grandfather, Ra. According to the Setites, Ra had executed Osiris' parents for having more children, seeing royal blood as a threat. This caused a lot of contention between the children and their grandfather, Ra. Set had left Egypt, bearing the name Sutekh, and was embraced while en route to Assyria. After the death of Ra, Osiris assumed leadership over Egypt becoming embraced by an Antediluvian Typhon.
The Setites have their own version as to why the brothers, Set and Osiris, had hated each other. It seems that all through childhood they rivaled each other. Perhaps Set was jealous that Ra chose Osiris to be ruler after death. Or maybe Set was upset that his wife, Nephthys, became a concubine to Osiris while he was absent from the kingdom for some time. Whatever the reasons, Set and his followers reject the teachings of Osiris, especially in the belief in preserving Humanitas.
Millenniums later, Sutekh returned to Egypt as Set. He was probably outraged after discovering that his brother was still alive, embraced as a vampire like himself. He waged war with his ancient brother Osiris, cleaving him into fourteen pieces. Then he scattered his body parts throughout Egypt. At least one of Osiris' children, Anubis, was also slain by Set. Osiris' other son, Horus, was either tortured to near-death or slain.
Isis, the wife of Osiris, kept her son Horus alive through magic (or resurrected him). Then the wizard Thoth came to her in a dream and told her how to resurrect Osiris. She desperately searched for her husband's body parts. When she collected all of the parts she could find of Osiris, she and the Children of Osiris, gave of their blood to their founder to restore him. His flesh mended together, becoming whole again, regaining consciousness even through Final Death.
Osiris was forever changed. He transcended the curse placed upon him by Typhon to attain true life once again. Though he could still heal injuries, his vitae could no longer sire childer, or even turn mortals into Ghouls. Since then, none of the Children have ever made their own Progeny. Their ranks come from lost or disillusioned Kindred or they recruit from other clans, especially from the Nosferatu.
After his final battle with Set, Osiris descended to the Underworld where he took his position to watch over Amenti, the Dark Kingdom of Sand. He remained dormant for millennia. When the Sixth Great Maelstrom struck the Underworld, Osiris awoke from this deep slumber. Amenti and all its resident spirits began to get shredded to pieces. He realized the Spell of Life which created the Undying was imperfect. Instead of creating a creature who was the epitome of life, it created a mockery of it, little better than the undead that the Undying fought.
As a result, several things occurred in a domino effect within a short period of time: All of the faithful Children of Osiris were turned, through Osiris' power, into normal mortals and the "unfaithful" were killed. A new Spell of Life was distributed to the Children, even to Isis cults. Thereafter, Osiris himself vanished from the Underworld, placing his essence into a network of magical sites known as the Web of Faith. No one knows if Osiris, in this new form, has any sort of consciousness anymore.
Disciplines and Lineage
Osiris was reported to manifest the "vigor of a thousand bulls" (likely a reference to either Fortitude or Potence), the "movement of the desert winds" (Celerity) and the "sudden irresistible power of his speech" (likely referring to Dominate) after his Embrace. No known Clan exhibits this combination of innate disciplines, combined with the talent of an Inceptor that first formed Bardo, leaving many scholars speculate that Osiris was, in fact, one of the first "true" Caitiff.
- Osiris and Set are said to be "flesh" brothers, mortals who existed 7,000 years prior to the Final Nights.