Brazil became a property of Portugal when the Portuguese arrived in our territory. They proclaimed themselves the owners of all the land from the Brazilian shore up to the Tordesillas line. Do you remember the line created by the Kings of Spain and Portugal to share the “new world” between them? Believe it. That was the ending border of Brazil.
The Hereditary Captaincies were created as a means to control and populate Brazil. Each captaincy had a grantee, an administrator chosen by the King.