It is actually based on history, who knows, maybe I get to read in SH a lot of interesting material for him. I understand that he was very curious.
Oda was very inspired by pirates and Vikings and aspired to become a manga artist.
Both Edward Newgate (Whitebeard), Marshall D. Teach (Blackbeard) and the commander of the Fourth Division Thatch, are based on the pirate who sailed the Caribbean in the 18th century, Edward Teach (also known as Edward Thatch), nicknamed Blackbeard.
The name "Roger" (from Gol D. Roger) is based on the name by which the pirates' flag is known, that is, the "Jolly Roger". On the other hand, the execution scene of Gold D. Roger is a direct tribute to the death of Olivier Levasseur, a 17th century pirate who possessed a necklace with a hidden message that supposedly revealed the location of all his treasures. Moments before he was executed, Levasseur took off his necklace and threw it to the public saying that whoever could decipher the message would find all his hidden treasures.
Roronoa Zoro: Her family name "Roronoa" comes from the name of the French pirate François L'Ollonais.
Eustass "Captain" Kid: From the 13th century pirate monk called Eustace the Monk and also comes from the 17th century Scottish pirate William Kidd.
X Drake: The 16th century adventurer and privateer Sir Francis Drake.
Basil Hawkins: John Hawkins, 16th century English pirate, and 17th century pirate doctor Basil Ringrose.
Trafalgar Law: From 17th Century Pirate Edward Low.
Jewelry Bonney: Its name comes from the 18th century pirate woman Ann Bonney.
Urouge: From Baba Aruj, one of the brothers of the Arab pirates of the 15th century.
Scratchmen Apoo: From the 19th century Chinese pirate Chui Apoo.
Capone "Gang" Bege: It comes from the famous American gangster Al Capone, and the English privateer William le Sauvage.
!!! And I've found this excerpt from the anime dealing with stolen history which is really funny. Enjoy!
