 From the time that Christopher Columbus landed in America there was a significant Iberian challenge facing large parts of the world for Spain and Portugal in conquering the Americas and many other territories around the world.In the east, Portugal held territories not only in Ceylon but in India, in the Persian Gulf, and what is now Indonesia, then referred to as the East Indies.From 1580 to 1640, the throne of Portugal was held by the Habsburg kings of Spain resulting in the biggest colonial empire until then (see Iberian Union).