"O Sole God beside whom there is none." -The Great Hymn to Aten
Atenism, also known as the Amarna heresy, took place during the 18th Dynasty reign of the Pharaoh Amenhotep IV, who later changed his name to Akhenaten. He introduced the worship of Aten, a sun deity, during year four of his reign. It is the earliest known monotheistic (belief in a single god) religion in history. At first he allowed the worship of the other established Egyptian gods such as Osiris, Isis, Horus, and Amun, setting Aten above all others as Supreme god.
In year five of Akhenaten's rule, construction began on the new capitol city Akhetaten, today known as Amarna. The location is thought to have been chosen by the pharaoh to be closer to Aten. It was during this time he changed his name from Amenhotep IV to Akhenaten as evidence to his worship of the sole god, Aten. In year seven, the Egyptian capital was officially moved from Thebes to Akhetaten even though construction continued for two more years. The move marked the "dramatic change in focus of religion and political power."
The move separated the pharaoh and his court from the political influence of priests and traditional centers of worship. In year nine, Aten was declared as not only supreme, but the ONLY god. Worship of all other deities (including idols, etc.) was forbidden. Defacing temples and images of Amun and the rest of the deities, establishing a strict unitarian monotheism. Unlike the other gods, Aten was protective and loving and did not require sacrifices. He was viewed not to punish but to gain allegiance and support through his loving presence. Aten's symbol became the solar disk, his loving rays descending down from the heavens upon his worshipers, (pictured above).
The banishment of all other gods within the Egyptian culture became equivalent of a widespread catastrophe. For twenty years Atenism replaced centuries of religious beliefs and practices. Akhenaten neglected politics, foreign policy and the economy deteriorated, focusing solely on his religious worship.
At the end of his reign, Akhenaten was isolated from the problems of his people. When he died, his successor, Smenkhkare, made a half hearted attempt to re-establish the old religions. It is argued by some experts that Smenkhkare was actually Akhenaten's famous queen, Nefertiti, disguised as a man. This is unlikely as the body of Smenkhkare was found in the Valley of the Kings. Also, in 2002, mummy number 61072 in KV35 is thought to be that of Nefertiti. (See the Discovery Channel special, "Nefertiti Rediscovered".)
At the death of Smenkhkare, Tutankhaten would take the throne at eight years old. Young and impressionable, the "Boy King" would prove to be the perfect ruler for the priests of the old gods and powerful advisers to mould and control. He would move the capitol back to Thebes and reestablish the old religions. He changed his name to Tutankhamun and restored order to the chaos caused by Akhenaten and Atenism.
For further reading of Akhenaten and Atenism, I suggest the book Akhenaten and the Religion of Light by Erik Hornung (Cornell University Press, ISBN: 978-0-8014-8725-5).
ROYAL BONDAGE, Pocket Books
PIRATE'S MISTRESS, Ellora's Cave