The Seven Warlords of the Sea, also known as the Shichibukai, played a crucial role in the One Piece series before their sudden removal from power. Known to be some of the strongest pirates, they used to be affiliated with the World Government, who offered them a certain degree of freedom on the seas in exchange.
The Shichibukai were all tremendously powerful and even made up one of the Three Great Powers in the One Piece world. Their intelligence, however, is just as underrated, and most made use of it to take advantage of their position.
10 Gecko Moria
Known to be a rival of Yonko Kaido back in the day, Moria is a pirate who once held the position of the Shichibukai. Sadly, after the Marineford War, he was removed from his position following an attempt on his life by a higher power in the World Government.
Moria isn't all that smart and his plan to become the Pirate King revolved around making use of Zombies that certainly wouldn't have lasted long in the New World.
9 Jinbe
Jinbe, also known as the First Son of the Sea, is one of the former Shichibukai who became important during the Paramount War saga for the first time. Being a powerful fighter, Jinbe was highly appreciated by the Government, however, his intelligence was just as important to them.
Through Jinbe, the World Government maintained relationships with Fishman Island. What's more, Jinbe himself took full advantage of his position by helping Fishman Island, the Sun Pirates, and even Arlong, showing his intelligent side.
8 Dracule Mihawk
One of the strongest characters in the story, Dracule Mihawk is the World's Strongest Swordsman. Until recently, he was quite possibly the strongest Shichibukai that the World Government had. Although Mihawk is strong, he hasn't shown to be all that smart, simply because he hasn't appeared in the story all that much.
Whatever little time Mihawk received on screen was spent showcasing his incredible strength. Nonetheless, Mihawk's demeanor certainly implies that he's a very shrewd fighter.
7 Buggy
While Buggy may be one of the weakest Shichibukai, he certainly isn't an idiot. Ever since the Impel Down arc, Buggy has proven to be extremely cunning and used every situation to his advantage.
With a little bit of luck, Buggy even landed the position of Shichibukai. Furthermore, he started a mercenary group called Buggy's Delivery and became a massive power in the New World, all without actually having any power.
6 Bartholomew Kuma
South Blue's Bartholomew Kuma was once known to be the most loyal Shichibukai. Not only did he help the Government on several occasions but he also offered his body for the Pacifista project, earning their trust even further. This, however, is likely a strategy of some sorts as his true allegiance was always pledged to the Revolutionary Army.
Kuma was intelligent enough to gain the World Government's trust. What's more, he cleverly saved the Straw Hat Pirates without anyone pointing fingers at them and even sent them to locations where they thought they would grow stronger.
5 Boa Hancock
The leader of the Kuja Tribe, Boa Hancock is among the strongest and the smartest people in the entire story. Although not focused on as much, Hancock is extremely intelligent, given that she has taken advantage of her position to get everything she wanted without any problems. She was smart enough to sneak Luffy into Impel Down and even managed to get the keys to Ace's cuffs.
Hancock makes use of her charm to get around people and it's safe to say that she can make a fool out of most people in One Piece.
4 Donquixote Doflamingo
One of the most dangerous Shichibukai, Donquixote Doflamingo was the King of Dressrosa at one point and he attained this position by masterfully removing Riku from power. Doflamingo has used his bloodline to the maximum advantage over the years and even gained power over the Celestial Dragons.
The Dressrosa arc showcased his smartness quite well and his cunning nature is why he is often known to be one of the most dangerous Shichibukai.
3 Trafalgar Law
One of the members of the Worst Generation, Trafalgar Law is quite easily among the most intelligent of characters. Not only is he a doctor with a tremendous amount of medical knowledge but he's also a skilled strategist.
Law is known to be a mastermind behind the Rocky Port Incident, following which became a Shichibukai. He used his position to get access to Punk Hazard and masterfully planned the downfall of Donquixote Doflamingo, which deserves incredible credit.
2 Crocodile
The first known Shichibukai to stand in Luffy's way, Crocodile is quite a powerful character but one especially known to be smart. His master plan in Alabasta saw him start a civil war that almost destroyed a country.
What's more, Crocodile is a man who had backup plans for his backup plans, showing how big a vision he had. His showings against Luffy and his plan to destroy Alabasta are enough to see him secure a high place on this list.
1 Marshall D. Teach
Currently, one of the Yonko, Marshall D. Teach, also known as Blackbeard was once a Shichibukai as well. He attained this position after defeating Portgas D. Ace and turning him over to the World Government. Teach was smart enough to lay low under Whitebeard's shadow and eventually struck when the time was right.
He then became a Shichibukai and used this position to gain access to Impel Down for powerful crewmates. Following this, Teach planned to steal Whitebeard's Devil Fruit with a shocking ploy, and, to everyone's surprise, he was successful. Eventually, he used his luck, power, and intelligence to become a Yonko.