Akhenaton, originally Amenhotep IV, ruled Egypt in the 1300s BC. He changed the capital from Thebes to Amarna during the fourth year of his reign and set the sun god Aten to be the principal god. It wasn't quite monotheism, but close.
Nefertiti is known to most of us through the beautiful painted limestone bust that was discovered in 1913, the work of the artist Thutmose, and resulted in giving her the title "The most beautiful woman in the world."
It was customary for Pharaohs to have more than one wife and Akhenaton had two others but Nefertiti was his Chief Wife and was the one who held his heart.
Reliefs from their time depict Nefertiti in poses of power, riding in chariots, smiting enemies, on battlefields. She became a priest and shared with Akhenaton the direct line to Aten. Normally only the Pharaoh would be considered to have the power to connect with gods.
Akhenaton and Nefertiti had six daughters and they are depicted in drawings as a devoted family. There are reliefs of Akhenaton presenting one of his daughters with jewellery, others of Nefertiti riding with him in a chariot or sitting on his knee or of Akhenaton kissing his wife in public. He took her to battle with him and they seem to have been inseparable.
It was a politically charged time in Egypt though, and not everyone was happy with the changes in religion made by Akhenaton. For some reason information is lacking on Nefertiti during the last years of Akhenaton's reign. It is possible she died then, but many scholars believe she took on another identity, and changed her name to Neferneferuaten , sharing the throne as co ruler with Akhenaton and even ruling under the name Smenkhkari after his death.
In recent years mummies have been found in the Valley of the Kings which might prove to be those of Nefertiti and her mother in law.
A description of Nefertiti's person and role comes to us from their times, perhaps part of her eulogy, "The Heiress, great in the Palace, fair of face, adorned with the double plumes, mistress of happiness, endowed with favours, at hearing whose voice the King rejoices, the Chief Wife of the King, his Beloved."