Atenism was one of the earliest monotheistic religions. It was the worship of the Egyptian sun god, Aten. It was started by the 18 dynasty pharaoh Amenhotep IV, better known as Akhenaten. It lasted 20 years, until Akhenaten's death. Tutankhamun, Akhenaten's son, restored the traditional Egyptian religion. Today modern day groups have attempted to revive Atenism as a worldwide religion, most notably Akhetaten Fellowship.