The first monotheistic Egyptian pharaoh was Amenhotep IV. Which name did he take to honor his one god?

He renamed himself Aken-Aten ("he who is of service to Aten.") in honor of the god.

You're right! Achnaten really angered some of the Egyptian priests, especially when he moved the capital. After his death, though, society returned to the religion and capital that it previously used.

Thanks for your answer, Yafa.