Keepers of the Black Flag

"Pirates exist for one reason or another. Fame, riches, power, and blood thirst are all factors that have pushed men and women to piracy. When the seas began to be stained with more pirate blood than necessary the leaders of many smaller crews got together to draft an alliance. They're the ones that defined our laws and they're the ones that keep order. They are the keepers of our worn black flag."

- The Legend of the Black Flag

The  are a mysterious organization to those outside the world of piracy, but to pirates they are what shaped the world as they know it. The were once the very pirates that drafted the rules of piracy. Governed by the seven pirate lords, this organization was coalition that offered aid to pirates but also let them know the laws of the world they lived in. To this day the mantle of the lords is usually taken by the strongest pirates in the new world who are not affiliated with the Yonko.

The seven lords also aren't entirely chummy though. Many have fought each other on multiple occasions. Other times members have banded together against threats. Though they all pursue their own goals they also all work to keep piracy alive. Yonko are usually not apart of or affiliated with the due to being crews that have grown so massive or powerful that they lack care for the laws and have their own business to attend to.

Trivia

 * Based on the idea of the Nine Pirate Lords from Pirates of the Caribbean.