Roger was the first named character shown in the One Piece series and the first person in general in the manga. He is the first character shown in the Anime due to being in the opening.
Roger is the first character to be shown with the D in his name; however, he is the second to be named. Dr. Kureha revealed that his true name was Gol D. Roger well after his initial introduction. This is also the first indication that there is an underlying mystery and something special in those who carry the initial D, and Roger himself admits to Whitebeard that the D has a greater meaning than a simple initial.
Roger is the first known owner of the straw hat that Luffy (and previously Shanks) wears.
During Shanks’ flashback back to Roger’s death and the day he last saw Buggy, rain can be seen falling down on the town at that moment. This is echoed by Luffy’s departure from Loguetown, as it also rained during his escape.
It was stated that Ace’s mother held him for 20 months (5 months before and 15 months after Roger’s execution).Since Ace’s birthday is January 1, Roger must have been executed sometime between late September and early October.
In Episode 85 of the anime, when Hiluluk was describing what a pirate is to Chopper, a man who was identical in appearance to Roger was seen.
When Oars was pretending to be a pirate by placing a piece of rubble on his head, a pirate similar to Roger was also shown.
In One Piece Green it was revealed that Roger’s mustache was actually nose hair (although this is probably a joke).
Upon his death, the real life pirate Olivier Levasseur had tossed a cryptogram from the scaffolding into the crowd and told them if they could figure out the message, his treasure (now valued at £160,000,000 in today’s money) would be theirs, a treasure that to this day has never been found. This seems to have been part of the inspiration for Roger’s legendary death speech, as Roger himself had delivered the message to find his treasure, and notably the poneglyphs are also part of a grand cryptogram leading to the end of the Grand Line.
Another possible inspiration for Roger could be Henry Every. In 1695, he captured an enormous treasure estimated to be worth up to £600,000 (around $400 million in modern currency), becoming the richest pirate in the world and earning him the epithet “The King of Pirates”. He is said to have influenced the next generation of pirates, including Blackbeard, Bartholomew Roberts, Calico Jack, Samuel Bellamy and Edward Low, among others, who were children at the time (and whose names are used for several One Piece characters).
Since Ace’s birthday is January 1, Roger must have been executed sometime between late September and early October.
