9. Ferdinand Magellan
Murder level: OCCASIONALLY MURDEROUS
How he died: STABBED TO DEATH
Although Magellan led the first voyage to circumnavigate the globe, he didn't actually survive the whole trip. He wasn't especially brutal throughout his trip, but Ol' Ferd had an unfortunate yen for proselytizing and converting the natives he encountered -- often through pain and death. This ultimately proved to be his undoing, when he took part in a beach skirmish on the Philippine island of Mactan and was promptly stabbed to death. Whether or not he was gellin' at the time remains a subject of scholarly debate.
8. Hernando de Soto
Murder level: CONSISTENTLY MURDEROUS
How he died: FEVER
In addition to "discovering" the Mississippi, de Soto's expedition into North America encountered a great number of native peoples. More often than not, these encounters resulted in hostility and outright slaughter, as de Soto's campaign followed the model established by his predecessors, Pizarro and Cortés, taking advantage of the Spaniards' advanced weaponry, tactics, and armored cavalry to combat native resistance and brand himself as a sort of living god.
Ultimately, though, de Soto didn't find the same level of riches seen previously in his conquest of Peru, and as he ventured deeper into the country in search of wealth, he fell ill and died of a fever on the banks of the Mississippi.