The ancient egyptian ruler who unsettled many of his country's social, religious, and artistic practices, was:

He was called Akhenaten

He was an ancient Egyptian pharaoh of the 18th Dynasty who ruled for 17 years. He abandoned the traditional polytheistic worship of Egypt and instituted a quasi-monotheistic faith based on Aten. His social and cultural revolutions were rejected and when he left power,the incoming dynasty destroyed any remnants of him from history until the 19th century when his aten city was discovered.