The Demon King Pirates and the Overlord Dragon Pirates had been rivals for years.
After the Rocks era ended, both crews occupied the southern waters of the New World Rear.
They clashed from time to time.
After the Overlord Dragon Pirates moved west, the two sides enjoyed a period of peace.
But they were only at peace because their territories no longer shared a border.
As their power grew and their territories met again, conflict inevitably erupted.
There had been no major war, but minor skirmishes never stopped.
Their officers, in particular, had nearly all fought along the border.
The Five Peaks Pirates held the north, while the Overlord Dragon Pirates held the west.
If the Demon King Pirates wanted to expand, they had to move north or west.
They bore an even deeper grudge against the Five Peaks Pirates than against the Overlord Dragon Pirates.
After all, once the Flying Pirates had risen to the top, the Five Peaks Pirates had lost vast stretches of territory.
To save face, they had set their sights on the Demon King Pirates.
The two sides had fought an outright war.
Because the Overlord Dragon Pirates had occupied Wano Country, most of their forces were stationed there.
They could maintain control over their other territories only through patrols.
That left their hold on those territories extremely fragile.
Seizing the opportunity, the Demon King Pirates had taken a small portion of their territory over the years.
If the great pirates of the New World had not spent those years standing together against the Navy, easing their tensions through that war, the two crews might have gone to war long ago.
Of course, in Demon King Nash's eyes, Overlord Dragon Zack was not his main rival. Ochoku was.
With Wano Country and now Dragon Island