The 15th and 16th centuries are known as the “Age of Discovery” or “Age of Exploration,” since it was a time when European leaders were funding global voyages, hoping that explorers would discover riches and new regions around the world to claim as their own. Portugal was a leader in this race, with many of their ships sailing around Africa shuttling cargo between Europe and Asia and Africa.

Columbus was determined to find a westward passage to these regions and propositioned first the Portuguese king, then leaders in Genoa and Venice, Italy, to lead a three-ship expedition across the Atlantic. Each of them rejected his idea. He then went to Spain. At first, Spain was busy with its Reconquista system—evicting Jews and Muslims out of their territory after centuries of war. Also, their nautical experts were skeptical of Columbus’s plan. So, they rejected him at first too—at least two times, according to historians. But by the end of the 15th century, their new regime was in place, and the country was able to focus on exploration and conquest in other regions. Soon after, in January 1492, Queen Isabella of Castile and Ferdinand II of Aragon of Spain agreed to sponsor his voyage.

Ultimately, the two parties united since they both desired fame and fortune, including victory in the “discovery race” and goods from gold to spices, as well as the opportunity to spread Catholicism across the world.

It is important to remember that in the 15th Century there was no unified country of Italy. Rather, Italy was made up of the Papal States and a number of city-states and their spheres of control. Therefore, there was no Italy for Columbus to go to for funding. Columbus did attempt to sell his idea of sailing west to Asia to the leaders of the Italian cities of Venice and his hometown of Genoa. However, they were uninterested. They already had well-established Meditteranean trade routes and thought it unwise to gamble on sending ships across the sea. Also, they did not want to run afoul of the Portuguese who were making a number of voyages of discovery out into the Atlantic at this time.

In fact, before he appealed to the Spanish, Columbus tried his luck with the Portuguese as well as the English. They also decided against supporting him.

When Columbus took his idea to the Spanish, Spain had only recently been united as a single Catholic nation. The Spanish monarchs were eager to get the upper-hand on the Portuguese who had established trade routes around Africa and outposts in India just a few years prior. They still were not sure that Columbus' idea would be fruitful, but they did finally agree to outfit him with three small outdated ships and a crew of just under ninety sailors figuring that they had more to gain than to lose in such a venture.

Queen Isabella and King Ferdinand only agreed to fund Christopher Columbus’s voyage after several attempts by the voyager to secure their support.

Columbus came up with the idea that a new route to Asia could be discovered by sailing west across the Atlantic. However, his distance calculations were overly ambitious, which made them questionable and unbelievable. He tried pitching his idea to the Portuguese, but they declined because of the calculations. 

Early attempts to convince the Spanish also failed. It took the intervention of King Ferdinand to allow Columbus to proceed with the journey. The king was motivated by the fact that a new trade route to Asia would help improve Spain’s status as a world power. There was also the fear that Columbus could pitch the idea to another country and that they would agree to the plan. The leadership also had the desire to spread Christianity. Spain had better access to the Atlantic than Italy, and the country was more likely to support the idea than Italy, based on logistics and the financing required.