Tutankhamun or Tutankhamen, was the third to last pharaoh of the Eighteenth Dynasty of ancient Egypt, who ruled c. 1332 – 1323 BC, dying at about the age of 18. Born Tutankhaten, his administration restored the traditional polytheistic form of ancient Egyptian religion, undoing a previous shift to the religion known as Atenism. Tutankhamun's tomb door proclaims his devotion to the ancient Egyptian gods.