Slave voyages were organized and left from all major Atlantic ports at some point over the nearly four centuries of the trans-Atlantic slave trade. Nevertheless, vessels from the largest seven ports, Rio de Janeiro, Bahia, Liverpool, London, Nantes, Bristol, and Pernambuco carried off almost three-quarters of all captives removed from Africa via the Atlantic Ocean. There was a major shift in the organization of slaving voyages first from the Iberian peninsular to Northern Europe, and then later back again to ports in southern Europe. A similar, but less pronounced shift may be observed in the Americas from South to North and then back again.