In 1453, when the Ottoman Turks took control of Constantinople and the surrounding areas, trade between Europe and Asia came to a complete halt, prompting the European nations to seek another route to their Asian trading partners; thus, they began looking for a sea route. The trip had always been fraught with danger, but Europeans no longer had access to products they had come to enjoy.
The only viable land route from Europe to Asia went through the Middle East and Turkey. Going further north through what would become Russia was even more dangerous than braving the robbers who would attack caravans in the Middle East.
Pepper and silk were two particularly popular products from Asia. Silk had been in high demand in Europe since the journeys of the explorer Marco Polo, and a network of traders from China, India, the Middle East and Italy would transport silk all the way to the European markets. The land route that traders had to take was known as the "Silk Road."
While England, Spain and Portugal were some of the most enthusiastic sponsors of early exploration, some of the most famed explorers like Christopher Columbus came from Italian cities like Genoa, which had long sent ships off to make trading expeditions.