So this is an old theory I discovered a while back, initially I was sceptical of it but found it interesting nonetheless so it kind of stuck to me. Since the reveal of Roger’s backstory I’ve come to believe it could be a possibility.

Basically it’s that Shanks travelled to the East Blue for the sole purpose to find Roger’s son Ace so that he could inspire him to inherit Rogers will and search for the One Piece but instead chose Luffy.

Following Roger’s backstory, Roger confidently believed his son would be the one to find the One Piece and finish what he couldn’t accomplish. After openly stating this despite not having a son yet it’s safe to assume that Rayleigh at least knew he was planning to have one before his death.

In regards to Shanks spending a year in the East Blue (the main point of this theory), I find it increasingly hard to believe that Shanks just casually found himself in the very town that Garp grew up and lives in despite having no personal connection or reason to be there (especially since it’s the home of an enemy) .

Thus comes in the idea that he most likely learnt of Ace’s existence through Rayleigh and went in search for him knowing he was being protected by Garp which lead him to Garp’s grandson, Luffy (realising he had potential). Or he came in contact with Roger’s son and after witnessing the hatred inside of Ace and his disdain towards the Pirate King he came to the conclusion that Ace had not inherited Roger’s Will and could never reach his heights, thus abandoning his notion of trying to influence Ace to reach Laugh Tale.

Now it’s been stated many times by Shanks that he sees Roger in Luffy, and after meeting him he was captivated by the boy’s words and realised he had the potential to inherit Roger’s Will and thus decided to influence/groom him (instead of Ace) into piracy which had led up to current events.

To further back this the idea of Shanks knowing about Ace – despite never being confirmed that the Roger Pirates knew (or didn’t know) of Ace’s existence – I find it hard to believe that at least Rayleigh (Roger’s first mate) was not aware of a son despite Roger telling his sworn enemy/rival Garp about it. Yes I know he entrusted him to Garp for his safety but I still find it hard to believe Rayleigh didn’t know.

People tend to use the fact that Rayleigh, Shanks or any of the Roger Pirates never interfered with the Ace’s execution or even approached him during his piracy as proof that they didn’t know of his existence. But in all honesty I don’t see why they ever would as it’s clear that Ace established that he wants no part of Roger since he took his mother’s name and it could be a possibility that he ran into a Roger Pirate and expressed his dislike to them(this is all speculation at the moment).

Additionally, at the end of Marineford, Rayleigh expressed sadness after Whitebeard’s death but showed no reaction/mention to Ace’s death or lineage which further proves that he may have already known who Ace was and how much he despised his father so he simply didn’t care for him – after all he had already acknowledged Luffy as the inheritor of Roger’s Will both in Sabaody and post timeskip.

As well with Shanks, it’s safe to assume that he had known about Ace’s lineage prior to Marineford. He expresses his shock to how similar his actions were to Roger but not by the fact that he was Roger’s son so it can be speculated that he’s known for a while.

What do you think? I love the idea that Ace was expected/meant to be “the chosen one” but instead Shanks discovered a hidden gem living in a bar in some backwater village and thus unknowingly awakened a beast that is our boy, Luffy.

*Theory by jujujustat