Amenhotep IV was probably in his late twenties when he was crowned. Mitanni king Tushratta sent his condolences on the death of Amenhotep III, addressing the new king for the first time as an equal. This letter was in response to one from Tiy (now queen mother), in which she requested that Tushratta write to her son in the same manner as he had to her late husband and he obliged. Tushratta later wrote the following to the new king, whose throne name, “Nefer-khepru-ra,” as usual, was mangled:

Interesting questions crop up with Tushratta's mention of Amenhotep IV as the “oldest” son. What were the names of the remaining princes? Is the mention of “Naphureya” as son of Tiy indirect evidence of the existence of sons by other wives? Could one of them have been a son of Sitamen or one of her sisters and Amenhotep III? Or even of Gilukhepa? Did any of them have official posts in their father's or brother's administration?

Transition to the new king was seamless, judging from representations in officials’ tombs. Carved on a back wall of Ramose's tomb is an enthroned king, with the goddess Ma'at standing behind him, receiving offerings from the tomb owner. The king's chunky figure style and elaborate jewelry are identifiable as those of Amenhotep III, even though the elements were only blocked in, with no details of facial features or jewelry before the sculptors stopped in the midst of their work, either because of the king's death or Ramose's absence. When work resumed, the details of the figures and jewelry were not finished, but the inscription, normally the last thing added to a scene after the fine details, was filled in, and it included the cartouche of Amenhotep IV. There was no need to change the image itself for the new king, as long as the name in the cartouche belonged to him.