 The Sahara has linked rather than divided the peoples who inhabit it and has served as an avenue for migration and conquest.Mauritania, lying next to the Atlantic coast at the western edge of the desert, received and assimilated into its complex society many waves of these migrants and conquerors.What is now Mauritania was a dry savanna area during classical antiquity, where independent tribes like the Pharusii and the Perorsi (and the Nigritae near the Niger river) did a seminomadic life facing a growing desertification.