The pinnacle of the religious hierarchy was the Pharaoh, both king and living god. Administration of the Egyptian kingdom was thus inextricably bound up with and largely controlled by the power and influence of the priests and scribes. Akhenaten's reforms cut away both the philosophical and economic bases of priestly power, abolishing the cults of all other deities and, with them, the large and lucrative industry of sacrifices and tributes that the priests controlled.
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https://en.wikipedia.org/wiki/Atenism