Aten (also Aton, Egyptian jtn) is the disk of the sun in ancient Egyptian mythology, and originally an aspect of Ra. The deified Aten is the focus of the monolatristic, henotheistic, monistic or monotheistic religion of Atenism established by Amenhotep IV, who later took the name Akhenaten in worship and recognition of Aten. In his poem "Great Hymn to the Aten", Akhenaten praises Aten as the creator, and giver of life. The worship of Aten was eradicated by Horemheb.
The Aten, the sun-disk, is first referred to as a deity in The Story of Sinuhe from the 12th dynasty, in which the deceased king is described as rising as god to the heavens and uniting with the sun-disk, the divine body merging with its maker. By analogy, the term "silver aten" was sometimes used to refer to the moon. The solar Aten was extensively worshipped as a god in the reign of Amenhotep III, when it was depicted as a falcon-headed man much like Ra. In the reign of Amenhotep III's successor, Amenhotep IV, the Aten became the central god of Egyptian state religion, and Amenhotep IV changed his name to Akhenaten to reflect his close link with the new supreme deity.
The full title of Akhenaten's god was "Ra-Horakhty who rejoices in the horizon, in his Name as the Light which is in the sun disc." (This is the title of the god as it appears on the numerous stelae which were placed to mark the boundaries of Akhenaten's new capital at Akhetaten, modern Amarna.) This lengthy name was often shortened to Ra-Horus-Aten or just Aten in many texts, but the god of Akhenaten raised to supremacy is considered a synthesis of very ancient gods viewed in a new and different way. The god is also considered to be both masculine and feminine simultaneously. All creation was thought to emanate from the god and to exist within the god. In particular, the god was not depicted in anthropomorphic (human) form, but as rays of light extending from the sun's disk.
Furthermore, the god's name came to be written within a cartouche, along with the titles normally given to a Pharaoh, another break with ancient tradition. Ra-Horus, more usually referred to as Ra-Horakhty (Ra, who is Horus of the two horizons), is a synthesis of two other gods, both of which are attested from very early on. During the Amarna period, this synthesis was seen as the invisible source of energy of the sun god, of which the visible manifestation was the Aten, the solar disk. Thus Ra-Horus-Aten was a development of old ideas which came gradually. The real change, as some see it, was the apparent abandonment of all other gods, especially Amun, and the debatable introduction of monotheism by Akhenaten. The syncretism is readily apparent in the Great Hymn to the Aten in which Re-Herakhty, Shu and Aten are merged into the creator god. Others see Akhenaten as a practitioner of an Aten monolatry, as he did not actively deny the existence of other gods; he simply refrained from worshipping any but the Aten.
The cult centre of Aten was at the new city Akhetaten; some other cult cities include Thebes, and Heliopolis. The principles of Aten's cult were recorded on the rock walls of tombs of Tall al-Amarnah. Significantly different from other ancient Egyptian temples, temples of Aten were open-roofed to allow the rays of the sun. No statues of Aten were allowed; those were seen as idolatry.  Priests had less to do, since offerings (fruits, flowers, cakes) were limited, and oracles were not needed.
During the Amarna Period, the Aten was given a Royal Titulary (as he was considered to be king of all), with his names drawn in a cartouche. There were two forms of this title, the first had the names of other gods, and the second later one which was more 'singular' and referred only to the Aten himself. The early form has Re-Horakhti who rejoices in the Horizon, in his name Shu which is the Aten. The later form has Re, ruler of the two horizons who rejoices in the Horizon, in his name of light which is the Aten.
- High relief and low relief illustrations of the Aten show it with a curved surface (see for example the photograph illustrating this article), therefore, the late scholar Hugh Nibley insisted that a more correct translation would be globe, orb or sphere, rather than disk. The three-dimensional spherical shape of the Aten is even more evident when such reliefs are viewed in person, rather than merely in photographs.
- There is a possibility that Aten's three-dimensional spherical shape depicts an eye of Horus/Ra. In the other early monotheistic religion Zoroastrianism the sun is called Ahura Mazda's eye.
- These two theories are compatible with each other, since an eye is an orb.
Egyptologists have vocalized the word variously as Aten, Aton, Atonu, and Itn.
Names derived from Aten
- Akhenaten: "Effective spirit of the Aten."
- Akhetaten: "Horizon of the Aten," Akhenaten's capital. The archaeological site is known as Amarna.
- Ankhesenpaaten: "Her life is of the Aten."
- Beketaten: "Handmaid of the Aten."
- Meritaten: "She who is beloved of the Aten."
- Meketaten: "Behold the Aten" or "Protected by Aten."
- Neferneferuaten: "The most beautiful one of Aten."
- Paatenemheb: "The Aten on jubilee.[clarification needed]"
- Tutankhaten: "Living image of the Aten." Original name of Tutankhamun.
- The Egyptian
- Great Hymn to the Aten
- Pharaoh of the Exodus
- The spatial symbolism of the Voortrekker Monument
- Wilkinson, Richard H. (2003). The Complete Gods and Goddesses of Ancient Egypt. Thames & Hudson. pp. 236–240
- M. Lichtheim, Ancient Egyptian Literature, Vol.1, 1980, p.223
- Fleming, Fergus, and Alan Lothian (1997). The Way to Eternity: Egyptian Myth. Duncan Baird Publishers. p. 52
- Jan Assmann, Religion and Cultural Memory: Ten Studies, Stanford University Press 2005, p.59
- M. Lichtheim, Ancient Egyptian Literature, Vol. 2, 1980, p. 96
- Dominic Montserrat, Akhenaten: History, Fantasy and Ancient Egypt, Routledge 2000, ISBN 0-415-18549-1, pp. 36ff.
- "Aten, god of Egypt". Siteseen Ltd. June 2014. Retrieved 22 December 2014.
- "History embalmed: Aten". 2014 Siteseen Ltd. Retrieved 22 December 2014.
- see Collier, Mark and Manley, Bill. How to Read Egyptian Hieroglyphs: 2nd Edition. Berkeley: University of California Press, 1998, p. 29