Christopher Columbus, often credited with "discovering" the Americas, can be considered a hero of many. Although Leif Eriksson is thought to have been the first to have sailed across the Atlantic, it was Columbus's triumphant return that led to the colonization of the New World by Europeans. To those settlers, this meant an escape from poverty, persecution, or prejudice--or even simply a renewed lease on life, an adventure. Columbus himself symbolized such adventure at the time, as did the many other explorers. Even today, what would the world be if the colonization of the Americas by Europeans had been delayed or, perhaps, had never occurred at all? Whether for better or for worse, the global political and economic landscape would be vastly different. To the early settlers and to admirers of the modern world as we know it, Columbus was indeed a hero.
To others, however, he is a despot that ought to have remained in Italy. With the arrival of European pioneers came also the arrival of European diseases. These diseases--smallpox, cholera, and tuberculosis, to name only a few--ravaged the Native American population, which had no immunity to such foreign bacteria and viruses. The great hero could, therefore, be called also a great slaughterer of men, exterminating a large fraction of an entire race. Further colonization led to further persecution of the Indians as white men sought to take the land for themselves. Tribes were herded onto reservations, social structures destroyed, and traditions rendered meaningless. Even today, many Native Americans are faced with poverty and joblessness.
As with anything, perspective is key. Is Columbus a hero or a tyrant? It depends largely on whom you ask.