The Romans had two naval outposts in the Atlantic coast of Africa: Sala Colonia near present Rabat and Mogador in southern Morocco (north of Agadir). The island of Mogador prospered from the local purple dye-making industry (highly esteemed in imperial Rome) from the reigns of Augustus until Septimius Severus. Augustus, based on the discovery of a sunken merchant ship from southern Hispania in the Djibouti area (done by his adoptive son Gaius Caesar when he sailed toward Aden), wanted to organize an expedition from Egypt to Mogador and Sala around Africa, but it seems that it never took place.