Final answer:
Christopher Columbus aimed to establish a trade route to the East Indies by sailing westward, funded by the Spanish monarchy with the hope of also expanding Catholicism. He mistakenly believed he reached Asia, and was unaware of the true significance of his discovery of the New World.
Step-by-step explanation:
Christopher Columbus's primary goal when he set out to explore the Atlantic Ocean was to find a new route to the rich East Indies. He believed, by sailing westward across the Atlantic, he would establish an efficient trade route to Asia, rich in gold, spices, and other commodities. His ventures were also motivated by a desire to expand Christianity. After facing rejections by various European monarchs, Columbus's proposal piqued the interest of Spanish monarchs Ferdinand and Isabella, particularly after the completion of the Reconquista. They financed Columbus's expedition, which led to the discovery of the New World, although Columbus himself believed he had reached the outskirts of Asia, particularly when he landed on Watling Island. His undertakings underscored Spain's intentions to compete with Portuguese exploration and gain a commercial advantage while also expanding Catholicism. Throughout his voyages, Columbus remained determined in his belief that he was establishing a route to Asia and was mostly unaware of the significance of his discoveries, taking to his grave the conviction that he had explored parts of the East Indies.