Abram von Toddy, more commonly known as Seabeard, was one of the most well-known pirates in the world. He wasn't the richest or the most powerful, but when it came to fear and ruthlessness, he had them in spades.
Born at sea to a slave merchant, he grew up surrounded by cruelty. His parents died of sickness when he was twelve, and he took the slave ship and all aboard it as his own, dubbing his ship "The Iron Maiden" after the infamous torture device. Through the years he refitted the Iron Maiden into a submarine, able to vanish into the waters to steak up on unsuspecting ships.
Now, age forty-five, he roams the seas, taking everything from sailors but quarter.

--
I know he kinda comes off as a Davy Jones ripoff, but believe me when I say that I came up with the idea long before Dead Man's Chest even came out.