DUAT (pronounced do-aht) was the realm of the dead in ancient Egyptian mythology. The deity Osiris was believed to be the lord of the underworld since he personified rebirth and life after death, being the first mummy as depicted in the Osiris Myth. The underworld was also the residence of various other gods along with Osiris. The DUAT was the region through which the sun god Re traveled from west to east each night, and it was where he battled Apep, who embodied the primordial chaos which the sun had to defeat in order to rise each morning and bring order back to the earth. It was also the place where people's souls went after death for judgement, though that was not the full extent of the afterlife. Burial chambers formed touching-points between the mundane world and the DUAT, and the akh, the effectiveness of the dead, could use tombs to travel back and forth from the DUAT.