The Akh meaning '(magically) effective one'), was a concept of the dead that varied over the long history of ancient Egyptian belief.

It was associated with thought, but not as an action of the mind; rather, it was intellect as a living entity. The Akh also played a role in the afterlife. Following the death of the Khat, the Ba and Ka were reunited to reanimate the Akh

According to the Pyramid Text #474 The akh belongs to the heaven, the corpse to the earth. The body is buried while the akh, the Shining One, ascends to the sky, becoming a star. It comes into being when ba and ka unite and is the part of the person least bound to the rest, leaving it behind in the quest for immortality. Rising to the heavens king Unas joined the stars: