In 1460 Pedro de Sintra reached Sierra Leone. Prince Henry died in November that year after which, given the meagre revenues, exploration was granted to Lisbon merchant Fernão Gomes in 1469, who in exchange for the monopoly of trade in the Gulf of Guinea had to explore each year for five years. With his sponsorship, explorers João de Santarém, Pedro Escobar, Lopo Gonçalves, Fernão do Pó, and Pedro de Sintra made it even beyond those goals. They reached the Southern Hemisphere and the islands of the Gulf of Guinea, including São Tomé and Príncipe and Elmina on the Gold Coast in 1471. (In the Southern Hemisphere, they used the Southern Cross as the reference for celestial navigation.) There, in what came to be called the "Gold Coast" in what is today Ghana, a thriving alluvial gold trade was found among the natives and Arab and Berber traders.