By the dawn of the Christian era, Southern Arabia is undergoing major changes; among these, the expansion of maritime trade at the expense of the old caravan route. This change is often described as something sudden, leading to a more perennial situation the ensuing centuries.We have chosen to take a new look at this case by first gathering all the epigraphic and historic data having to do with pre-Islamic ports in the Red Sea and the Aden Gulf, from when they were first founded 'till the 7th century. This global outline then has then allowed us to describe the evolution of the maritime economy all along the first centuries of the Christian era, the nature of the trading places and the part political power plays in overseeing this new eco...