Osiris is one of the most prominent deities in the ancient Egyptian pantheon, serving as the lord of the underworld, the judge of the dead, and a powerful symbol of resurrection and fertility. Originally a benevolent king who taught humanity agriculture, laws, and the arts of civilization, he became the ruler of the afterlife following his betrayal and murder by his brother, Set. The Myth of Osiris

The narrative of Osiris is the most detailed and influential story in Egyptian mythology. Osiris | Description, Myth, Symbols, & Facts - Britannica