Akhenaten, also known as Amenhotep IV, was king of Egypt during the Eighteenth Dynasty and reigned from 1375 to 1358 B.C.E. Called the "religious revolutionary," he is the earliest known creator of a new religion. The cult he founded broke with Egypt's traditional polytheism and focused its worship on a single deity, the sun god Aten. Erik Hornung, one of the world's preeminent Egyptologists, here offers a concise and accessible account of Akhenaten and his religion of light.