The Emperors of the Sea, also known as the Yonko, have played a significant role in the overarching story of One Piece. Although they have been active in the world of One Piece since the very beginning, they were explained by Eiichiro Oda properly in the story in One Piece chapter 432, which was released on October 30, 2006, in Shueisha's Weekly Shonen Jump issue 48.

In the 20 years that have passed since then, the Emperors made their presence known on the high seas of the One Piece world. But now, this order is finally being dethroned. While the Yonko maintained their dominance for 20 years, one of the Four Emperors is growing at an unprecedented speed, leaving the others in the dust. For the first time since the era of the Pirate King, a new unrivaled supreme king of the seas is emerging in the form of Luffy, who leads the Straw Hat Pirates. The Straw Hats, having gained two more Conqueror's Haki users, are now leaving the other Emperor crews behind and quickly establishing themselves as the true rulers of the seas in the climax of the Elbaf arc.

The Four Emperors have been the primary antagonists of the second half of the story, up until the Final Saga. In fact, after the events of the Dressrosa Saga, One Piece officially entered what is known as the “Versus Four Emperors Saga,” where Kaido and Big Mom, two of the Four Emperors, were the main antagonists. In the Wano Country arc, two of the Four Emperors finally fell.

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