Whatever it is, the answer is NOT Hernan Cortes. He was a very famous Spanish explorer.
Other famous explorers consist of Francisco Pizzaro, Hernando de Soto, Vasco Nunez de Balboa, Juan de la Cosa, and many more. Hope this could help eliminate some answers.
Because many believed there could be gold and many other riches that were undiscovered and also wished in claiming new land for wars in case another broke out