In Greek mythology, Belus (Ancient Greek: Βῆλος Bē̂los) was a king of Egypt and father of Aegyptus and Danaus and (usually) brother to Agenor. The wife of Belus has been named as Achiroe, or Side (eponym of the Phoenician city of Sidon). Diodorus Siculus claims that Belus founded a colony on the river Euphrates, and appointed the priests-astrologers whom the Babylonians call Chaldeans who like the priests of Egypt are exempt from taxation and other service to the state.