In the rich variety of traditional accounts about the birth and life of Moses, a special place is always reserved to his double nationality. In the biblical text of Exodus 2-3 Moses is Egyptian because of the reversal of an element in the traditional "story of the hero who was exposed at birth", the adoption of the abandoned infant by a commoner (like the gardener of Sargon the Great, the herdsman of Cyrus, the swineherd of Romolus and Remus): he is adopted by an Egyptian princess, becoming a prince himself and a potential heir to the throne of Egypt. As expected, authors and texts from the Egyptian Diaspora, like Artapanus, Ezekiel Tragicus, Philo of Alexandria and Josephus, put a strong emphasis on Moses' princely education, his devotion to adopted parents, and his legitimacy as Egyptian heir, with both apologetic and polemical intentions. In my paper I will search the meanings attached to this ethnical identity of Moses, exploring how each biblical and extra-biblical text used its set of ideas and data about Egyptian culture and civilization to build its own image of the Lawgiver.