The ancient Egyptian underworld or realm of the dead was called the Duat.
The Duat was a complex supernatural region associated with the night journey of the sun god Ra and with the passage of deceased souls. Egyptian texts describe gates, waterways, caverns, guardians, and dangerous beings that travelers had to overcome with knowledge and magical protection.
The dead did not automatically reach the blessed afterlife simply because they had been buried. They had to navigate the Duat and face judgment. Funerary compositions such as the Book of the Dead, the Book of Gates, and the Amduat supplied names, spells, and maps for this journey.
The Duat should not be treated as exactly identical to the Field of Reeds. Aaru was the ideal destination, while the Duat was the larger underworld environment. Anubis guided and protected the dead during this transition, although Osiris remained its principal ruler.