Who wrote King of Eternity?

Answer 1

You Could be referring to the writings in the Ancient Egyptian Book of the Dead, if so, it was most likely written by Egyptian Priests. A Brief Explanation follows, then the part contains the line in your Question From the New Kingdom onwards a Book of the Dead papyrus became an essential part of the funerary equipment and every Egyptian who could afford to acquire a copy was buried with it close at hand for use in the afterlife. That is why so many and varied examples have survived and why so much has been learned about the text which has been called erroneously but very evocatively the Bible of Ancient Egypt. Introductory Hymn to Osiris Worship of Osiris Wennefer, the Great God who dwells in the Thinite nome, King of Eternity, Lord of Everlasting, who passes millions of years in his lifetime first-born son of Nut, begotten of Geb, Heir, Lord of the Wereret-crown, whose White Crown is tall, Sovereign of gods and men. Hope this answers your Question