Akhenaten (; also spelled Echnaton, Akhenaton, Ikhnaton, and Khuenaten; meaning "Effective for Aten"), known before the fifth year of his reign as Amenhotep IV (sometimes given its Greek form, Amenophis IV, and meaning "Amun Is Satisfied"), was an ancient Egyptian pharaoh of the 18th Dynasty who ruled for 17 years and died perhaps in 1336 BC or 1334 BC. He is noted for abandoning traditional Egyptian polytheism and introducing worship centered on the Aten, which is sometimes described as monolatristic, henotheistic, or even quasi-monotheistic. An early inscription likens the Aten to the sun as compared to stars, and later official language avoids calling the Aten a god, giving the solar deity a status above mere gods.
Akhenaten tried to bring about a departure from traditional religion, yet in the end it would not be accepted. After his death, his monuments were dismantled and hidden, his statues were destroyed and his name was not to be included in the king lists. Traditional religious practice was gradually restored, and when some dozen years later rulers without clear rights of succession from the 18th Dynasty founded a new dynasty, they discredited Akhenaten and his immediate successors, referring to Akhenaten himself as "the enemy" or "that criminal" in archival records.
He was all but lost from history until the discovery during the 19th century of the site of Akhetaten, the city he built and designed for the worship of Aten, at Amarna. Early excavations at Amarna by Flinders Petrie sparked interest in the enigmatic pharaoh, and a mummy found in the tomb KV55, which was unearthed in 1907 in a dig led by Edward R. Ayrton, is likely that of Akhenaten. DNA analysis has determined that the man buried in KV55 is the father of King Tutankhamun, but its identification as Akhenaten has been questioned.
Modern interest in Akhenaten and his queen Nefertiti comes partly from his connection with Tutankhamun (even though Tutankhamun's mother was not Nefertiti, but a woman named by archaeologists The Younger Lady), partly from the unique style and high quality of the pictorial arts he patronized, and partly from ongoing interest in the religion he attempted to establish.