Akhenaten, originally Amenhotep IV, was a transformative pharaoh of ancient Egypt known for his radical shift to monotheism, worshiping the sun god Aten. His reign (1353-1336 BCE) marked a departure from traditional polytheism, leading to the closure of temples and a new capital, Akhetaten. Despite facing resistance and a decline in political power, his unique vision and artistic innovations have left a lasting legacy, making him one of history's most controversial rulers.