I'm sure you remember the story that the king wouldn't give Columbus any mosey from the public treasury so queen Isabella had to hock her private jewels to pay him.
The story about pawning the royal jewelery is a fairy tale. Isabella of Castile and Aragon was more than just the spouse of the King, she was a co-regent, having brought her own kingdom into the union. Ferdinand and Isabella established a commission to review Columbus' proposals. At the time (1486-1492), F&I were focused on removing the Moors from the Iberian Peninsula.
Columbus made exorbitant demands of the rulers and they basically told him to "get lost." However, Royal advisors convinced the rulers that there was a strong profit motive to establish trade routes to the "Indies". Columbus was recalled and he was knighted, given an admiralty, made a hereditary viceroy. Columbus has also acquired a well-connect partner, Martin Alanzo Pinzon. The first Columbus expedition was both privately and publically funded, and for Spain, resulted in a position as one of the world's great powers.