Four Emperors

4 Pirate Emperors
4 great pirates who rules the second half of the Grand Line. They are one of the 3 great powers. Each of them is equal in strength to Whitebeard and whenever there is a shift in the balance of the 3 powers (like Crocodile loosing his status as shichibukai) one of the 4 Pirate Emperors makes a move.

List of Pirate Emperor
1. Shanks

2. Whitebeard

3.

4.