In 1441, Gonçalves was sent by Henry the Navigator to explore the West African coast in an expedition under the command of Nuno Tristão.
As Gonçalves was considerably younger than Tristão, his duty was less exploration than it was hunting the Mediterranean monk seals that inhabit West Africa.
After he had filled his small vessel with seal skins, Gonçalves, on his own initiative, decided to capture some Africans to return to Portugal.
[1] An alternate record shows that Gonçalves had captured a chief and two of his subjects who were fishing in an area claimed by Portugal.
An Arab which had come with Tristão expedition was sent inland to tell the local populations about ransom negotiations for the captives, as well eventual business they would like to do.