The reign of Pharaoh Akhenaten/Amenhotep IV is controversial. Although substantial evidence for this period has been preserved, it is inconclusive on many important details. Nonetheless, the revolutionary nature of Akhenaten's rule is salient to the modern student of ancient Egypt. The king's devotion to and promotion of only one deity, the sun disk Aten, is a break from traditional Egyptian religion. Many theories developed about this era are often influenced by the history of its rediscovery and by recognition that Akhenaten's immediate successors rejected his rule.