A young man from Genoa, without a knowledge either of the classics or of the Fathers, and with no other argument except his own fixed belief and some vague talk about bits of wood and shipwrecked mariners, was not the person to inspire the capitalists of Portugal.

Yet the thing had to be done.
Obviously it could not be done at Porto Santo, where there were no ships and no money.

Influence must be used; and Columbus knew that his proposals, if they were to have even a chance of being listened to, must be presented in some high-flown and elaborate form, giving reasons and offering inducements and quoting authorities.

He would have to get some one to help him in that; he would have to get up some scientific facts; his brother Bartholomew could help him, and some of those disagreeable relatives-in-law must also be pressed into the service of the Idea.
Obviously the first thing was to go back to Lisbon; which accordingly Columbus did, about the year 1483..