The first successful settlement of São Tomé, an uninhabited island before the arrival of the Portuguese sometime around 1470, had been established in 1493 by Álvaro Caminha, who had received the land as a grant from the crown.

Príncipe had been settled in 1500 under a similar arrangement.

Attracting settlers has proved difficult, however, and most of the earliest inhabitants were "undesirables" sent from Portugal, mostly Jews.

In time these settlers had found the volcanic soil of the region suitable for agriculture, especially the growing of sugar.

São Tomé is right on the equator and wet enough to grow sugar in wild abundance.

Its proximity to the African Kingdom of Kongo provides an eventual source of slave labor to work the sugar plantations.

The cultivation of sugar is a labor-intensive process and the Portuguese begin to import large numbers of enslaved people from the mainland.

São Tomé and Príncipe are taken over and administered by the Portuguese crown in 1522.