Francisco Pizarro - Fransico Pizarro was the Spanish conqueror of Peru.
Vasco Nuñez de Balboa - was a renowned explorer, conqueror, and the governor of Spain.
Hernando De Soto Hernando De Soto of Spain was born in 1500. He was the first to lead a European expedition to America, and discover the Mississippi River
Ferdinand Magellan - Discovery of the New World by this famous explorer.

IF OTHERS USE THEM IF YOU LIKE.. :)

( More about them: http://www.buzzle.com/articles/famous-spanish-explorers-and-conquerors.html )