Portuguese discoveries a ground-breaking voyage commanded by Vasco da Gama. The squadron of Vasco da Gama left Portugal in 1497, rounded the Cape and continued along the coast of East Africa, where a local pilot was brought on board who guided them across the Indian Ocean, reaching Calicut in western India in May 1498. The second voyage to India was dispatched in 1500 under Pedro Álvares Cabral. While following the same south-westerly route as Gama across the Atlantic Ocean, Cabral made landfall on the Brazilian coast. This was probably an accidental discovery, but it has been speculated that the Portuguese secretly knew
Portuguese discoveries tip of Africa, disproving the view that had existed since Ptolemy that the Indian Ocean was separate from the Atlantic. Also at this time, Pêro da Covilhã reached India via Egypt and Yemen, and visited Madagascar. He recommended further exploration of the southern route. As the Portuguese explored the coastlines of Africa, they left behind a series of padrões, stone crosses inscribed with the Portuguese coat of arms marking their claims, and built forts and trading posts. From these bases, the Portuguese engaged profitably in the slave and gold trades. Portugal enjoyed a virtual monopoly of the Atlantic slave trade