Who were the first known monotheists?

The first known monotheists are often believed to be the ancient Hebrews, particularly during the time of the biblical figure Moses, who is traditionally associated with the establishment of monotheism in ancient Israel. This belief in a single, all-powerful God is foundational to Judaism. However, some scholars also point to earlier influences, such as the religious reforms of Pharaoh Akhenaten in ancient Egypt, who promoted the worship of a single deity, Aten.