Snoke is Gallius Rax.
Snoke is actually Gallius Rax. Makes sense. Snoke mentioned he was around to see the rise of the empire, so was Rax. It was said Snoke was once very handsome, Rax was considered so.
http://vignette3.wikia.nocookie.net/star-wars-canon-extended/images/f/f9/Rax.jpg/revision/latest?cb=20160715082032
This was put out there a while ago, but not a lot of people talk about it, mainly because Rax isn't well known to the common Star Wars fan. But;
Rax is an orphan living on Jakku during the time of the Galactic Republic and he is befriended by Sheev Palpatine who appears to be doing Sithy things on the planet.
Gallius has Force Sensitivity and is actually able to resist the power of Palpatine, which of course makes him very valuable to the future Emperor.
Rax becomes a puppet master and special advisor to the Emperor. He’s the one pulling the strings behind the scenes.
When Rae Sloane looks at him, it’s like she’s looking at a hologram.
He’s described as being very pale and his eyes as black holes.
He believes it’s very important for the Empire to recruit children and indoctrinate them at a young age. This is exactly what the First Order does as opposed to a clone army in The Force Awakens.
By the end of the book Life Debt he’s calling himself Emperor Rax.
I believe there's more. Sidious was looking for something dark side related in Jakku it's known. During the final battle there Rax most likely journeyed down to whatever was buried beneath the surface and may have merged with the slumbering entity.
*Also; they stated Snoke was someone you haven't seen before. We haven't seen Rax onscreen anywhere before.
Right now I'd say that's the best theory. Fits all the pieces pretty well. share