Ieru is a Berber lunar deity attested by a Roman-period rock inscription at Guechguech in Numidia, above which is carved a human head with a radiate crown, the standard iconography of an astral god. His name is philologically linked by Gabriel Camps to the Berber word for the moon, ayyur (archaic (y)yur), making him a rare named embodiment of the moon-worship that ancient writers ascribed to the Libyans: Herodotus (Histories 4.188) reports that the Libyans sacrificed to the sun and the moon, and Ibn Khaldun likewise recalls Berber veneration of these luminaries. Ieru thus provides an individuated cultic name for the widely noted but otherwise anonymous Berber cult of the moon.