Oooh, history! My favorite subject! Let's dip a little bit past Soviet rocket insanity and the second world war 2, to my personal specialty! Egypt!
In particular, a specific period of the 18th Dynasty (1353-1356BCE) known as the Amarna Period
So. It's 1535, and the much, much loved Pharaoh Amenhotep III has died after 39 long, productive years on the throne, controlling an empire from the 4th Cataract of the Nile River (down into Punt), all the way up to the Euphrates river! That's a big loving empire. His favored son, Crown Prince Thutmose, had died a few years before, so it comes down his younger son, Amenhotep IV to take the throne.
So he does, and becomes a new Pharaoh. There's much rejoicing and partying and so on, but things do not stay happy long. If you know anything about Egypt, you know that their religion was heavily polytheistic, meaning they worshiped several gods, making up an entire pantheon which weighed heavily on day-to day life. Art, music, architecture, all of it is very heavily involved in this religion as well. The priests who take care of religious rites are a very important caste in Egyptian society.
Amenhotep IV decides "Nope fuck that noise". Within 4 years, he has done away with the traditional religion, and replaced it with the worship of the sun disk, named Aten. He goes as far as to reject his father's name, and takes the name Akhenaten, which means basically "Beloved of Aten".
Naturally, the priests of the old system are right pissed at this turn of events. In a snap of the fingers, the Pharaoh has made them all irrelevant. Looking around the capital, Thebes, Akhenaton decides he doesn't like it there anymore. Too old-religiony for him. So he has a brilliant idea. Let's build a brand new capital in the middle of the bloody desert! And because he's Pharaoh, and chief priest of the new religion, the people follow, and thus the new city of Amarna(Ancient name Akhentaten (Horizon of Aten) is built. It's 400 kilometers north of the ancient capitol of Luxor.
The worship of Aten brings a whole lot of changes. There's this weird 15 years in Egyptian art where the traditional style, where people and Gods were drawn somewhat uniform in size and figure;

Changed for HIGHLY stylized looks. Men (especially Akhenaten) become highly feminine, with wide hips, highly angular faces, and sometimes breasts!
(We don't know who the baby was. The woman on the right is Nefertiti)
The Egyptian people go along with the change, right up until Akhenaten dies in 1336-1335BCE. There's something of a power struggle in this time, with a very shadowy figure called Smenkhare (Who POSSIBLY could be Nefertiti, or one of hers and Akhenaten's children), then onto his son Tutankhaten. (No I didn't spell that wrong) By this time, the people are fed the gently caress up. They want their old time religion back, they hate Amarna, they wanna go back to the old ways. Tutankhaten changes his name to the familiar Tutanhkamun (Living image of the god Amun), and within 2 years of his father's death every trade of the Amarna period religion is wiped clean.
Tut reigns for a very short period of time, and his line is so inbred there's no heirs to take over. There's another period of fighting and military control before the man who would be known as Ramses I takes the throne.
Egyptian people were SO pissed off with Akhenaten and his progeny that they erase them from history as best they can. Akhenaten's tomb is desecrated, and the face on his coffin is chipped off, as is his royal cartouche.

The same would have happened to Tutanhkamun but his tomb was forgotten about very quickly as he was a minor king, which is why it was found intact.
The Amarna period was largely forgotten by history until about 1892, when Sir Flanders Petrie started digging, and interest in the "Heretic King" re-emerged.
Interesting (gross) fact! In 2010 DNA testing confirmed that Tutankhamun was the definite son of Akhenaton. But...they also found that his MOTHER shared the same grandparents as his father. Yup. Tut was the product of Akhenaton and his sister.