Final answer:
King Ferdinand and Queen Isabella of Spain promised Christopher Columbus a title of nobility and a share of the treasures from his voyages as a reward for a successful trip that aimed to find a new route to India and spread Catholicism.
Step-by-step explanation:
The king and queen of Spain, Ferdinand and Isabella, thought of rewarding Columbus for a successful trip by offering him a title of nobility and a percentage of the riches he would find. The Spanish monarchy was interested in spreading Catholicism and gaining a commercial advantage over Portugal.
They sponsored Columbus's expedition in the hopes of finding a new route to India, expanding trade, and spreading their faith.
Columbus was promised 10 percent of the gold, silver, spices, and other valuables he obtained. Despite the initial skepticism from many European monarchs regarding his calculations about the size of the earth and the distance to Asia, the Spanish monarchs decided to support his venture after the Reconquista.
Columbus's voyages did not produce the expected riches, but they sparked extensive Spanish exploration in the New World. Later, the exploitation of native people through systems such as encomienda would become a means of reward for conquistadors.