Long before the Pirate era had reached the zenith of their time, four kingdoms constantly fought each other for a very long time. Then it all began to change when all those civilizations were slowly submerged by the sea. In order to survive, they began to migrate continuously to higher lands, leaving behind what was once the most prosperous lands, and made a habit of living on sloops. However, wars continued to break out, civilizations gradually gathered together to form Four Great Kingdoms: the North, the South, the West, and the East..
The scope of the Kingdoms was too large, so the wars of conflicts and territorial encroachment were taking place every day and every hour. They gradually consumed the resources of the kingdoms and inhibited the development of the Kingdom. Realizing this all, the Four Great Kingdoms agreed to sign a peace pact to prevent territorial conflicts. They decided to limit their property to specific regions. In order to avoid conflicts, the borders of this Kingdom were set to be far away and not adjacent to each other. The Kingdoms all have one common law: "Those dare to leave the territory of the Kingdoms shall suffer from a tragic death."
Still, there are those who do not want to be restrained by this law. There are those who choose to rob other ships for a living and hide in the sea. There are prisoners who escape Kingdoms' prisons and adventure seekers. But for whatever reason, these guys all call themselves Pirates. As time passed, the number of these people increased so many that it was called the era of pirates – Pirate Land Online.