Nicolas V (15 November 1397 – 24 March 1455) was pope of the Roman Catholic Church, from 1447, to his death, in 1455. His real name was Tommaso Parentucelli. His father was a doctor, and he was the first humanist pope. Some of his successes were the resignation of Amadeus VIII, who was an Anti-pope, in 1449. He made a Papal Bull, called Dum diversas. In it, he authorized Afonso V of Portugal to to conquer the lands of the non-believers, to chase their inhabitants away, to subjugate them, and to put them into a state of slavery. This legitimized colonialism. There was also the Fall of Constantinople, in 1453, which ended the Eastern Roman Empire.