The earliest European accounts of the Lower Guinea coastlands are fewer and less informative than those available for the coastlands of Upper Guinea. This is not surprising. The exploration of the 900 or so miles of the Guinea coast to about as far as Cape Mesurado was a more deliberate process, over some eighteen years, than was that of the nearly 2000 miles of coast between Cape Mesurado and Cameroun, which seems to have been undertaken essentially in the five years, 1471/75. It was also probably a more open process, involving sailors and merchants of many nations besides the Portuguese, men who were full of a Renaissance wonder at what they saw and keen to communicate their new knowledge. Some of these men or their followers were soon – certainly by about 1500 – residing more or less permanently in African communities on the Upper Guinea coasts, subject to little or no effective control from the Portuguese authorities, becoming lançados. On the other hand, by the later 1470s the discovery of the gold wealth of Mina had led the Portuguese crown to seek to establish a royal monopoly over sea trade with Lower Guinea, and to confine it to a few posts over which it sought to assert its direct control.
The first comprehensive account of the Upper Guinea coasts to have survived is to be found in the Esmeraldo de Situ Orbis of Duarte Pacheco Pereira, almost certainly written between the years 1505 and 1508. It is constructive to compare this work with its contemporary, the Description of the West Coast of Africa written by Valentim Fernandes, probably in 1506 or 1507, which describes the Guinea coast only as far as Cape Mount (although it also has fascinating accounts of the islands of São Tomé and Annobón in the Gulf of Guinea).