Tutankhaten was the son of Akhenaten. When Akhenaten died, his brother, or perhaps mother, called, Smenkhkare, ruled for a short while, then died and the throne passed to Tutankhaten. Tutankhaten renounced the new religion of his father (probably because of powerful priests and advisers) and changed his name to Tutankhamun, or 'living image of the god Amun'.
Although he died young, Tutankhamun played an important part in Egyptian history.
