Summary
The former Pirate King, Gol D. Roger was an incredibly powerful figure in theOne Pieceworld who defined an era. Perhaps, it can be said that he was the most influential pirate of all time and the one who can be considered to be the pinnacle of piracy itself.
Even though piracy wasn’t all that common during Roger’s age, there were still quite a lot of incredibly powerful pirates sailing the seas. Roger was certainly among the best of the crop, however, at the same time, there were other powerful pirates who made a name for themselves and inducted themselves into the history books.

8Kaido
Kaido Was Building Up His Strength In Roger’s Era
Kaido was certainly a powerful pirateduring Roger’s age, however, he was far from his full strength. Judging by the events of the God Valley, it appears that Kaido fought Roger at some point before this incident took place and lost.
Nonetheless, Kaido was still an apprentice on Rocks’s ship and was still building up his strength.

7Silvers Rayleigh
Rayleigh Was Considered To Be A Legendary Fighter
Known as the Dark King, Rayleigh was the right-hand man of Roger and certainly an incredibly powerful pirate. As the Vice Captain of the Roger Pirates, he certainly had authority over every single other member of the crew.
He was so strong that even in his old age, Garp considered the Navy to be insufficient to be able to take him down without preparations. Rayleigh could fight against any Yonko in his prime, however, in his old age, he believes that he is not strong enough.

6Kozuki Oden
Oden Would Have Defeated Kaido
Oden is another underestimated pirate that fans believe was far weaker than Roger. While it is true that Oden was weaker than Roger when they first fought, it must be remembered that he returned to Wano several times stronger.
In fact, by this point, Oden had built up his strength to a level where he could even defeat Kaido. In his prime, Oden would certainly have been one of the strongest pirates from Roger’s own generation.

5Charlotte Linlin
Linlin Was A Powerful Yonko
Charlotte Linlin was yet another incredible pirateduring the era of Roger. In this era, Linlin was certainly not at her strongest, however, her strength was building with each passing year. Charlotte Linlin became a Yonko and acquired a massive family as well.
In the end, she conquered a big portion of the New World and established herself as a mighty force on the seas. Her strength was certainly enough to rival Roger in combat, however, defeating him would have been very difficult for her.

4Shiki
Shiki is a pirate who is underestimated by fans quite a lot. This is because of the inaccurate portrayal in the non-canon Strong World film. However, Shiki possessed incredible strength, such that even Roger could have succumbed to his power.
The Battle of Edd War that was fought between the Roger Pirates and the Golden Lion Pirates could easily have been won by him had a storm not struck. This battle ended up being a tie. Nonetheless, Shiki, as a pirate, was a worthy opponent for Roger and someone in the same league as him.

3Edward Newgate
Newgate Could Match Roger In Combat
Edward Newgate, famously known as Whitebeard, is one of the strongest pirates to have ever lived in the One Piece world. Whitebeard was certainly strong enough to fight against Roger and one of the very few to match him in combat.
Whitebeard possessed the powers of the Gura Gura no Mi and with the power of this Devil Fruit he could destroy the entire world if he so willed. This Devil Fruit gave him the title of the Strongest Man in the World and, with all his powers, he could match Roger in combat when they last fought. Clearly, he was among the shining stars from Roger’s generation.

2Gol D. Roger
Roger Was On Top Of The Era
The Pirate King, Gol D. Rogerhimself was an incredibly powerful pirate and certainly one of, if not the most, strongest of his own generation. Roger did not possess any Devil Fruit, however, the strength of his Haki was such that he was considered to be the strongest of all time.
Roger was powerful enough to match Whitebeard even when he was ravaged by a deadly sickness. Undoubtedly, he would’ve been the greatest pirate of all time in his prime.

1Rocks D. Xebec
Rocks Was Stronger Than Roger
The man who aimed to be the King of the World,Rocks was an incredible piratewho lived around the same era as Roger. Not much is known about him, however, what fans do know is that he possessed incredible strength, such that Roger had to team up with Garp to defeat him.
According to the legends, Rocks is the fiercest rival that Roger has ever had in his entire life. It appears that these two characters have fought on multiple occasions, with Roger being bested by Rocks on at least one of them. He was certainly the strongest pirate from Roger’s generation.

One Piece
Cast
One Piece is a Japanese manga written and illustrated by Eiichiro Oda. The series follows protagonist Monkey D. Luffy and his Straw Hat Pirate crew as they explore the Grand Line to find the King of the Pirates' ultimate treasure, the One Piece, in order to become the next king. The manga’s popularity helped it spin off into a larger media franchise, including an anime with more than 1,000 episodes.