As in, a RP that takes place in the past?
I've done that sort of thing before on other games. Wildstar's housing system makes such a thing very possible, build/scene wise.
I've had a lot of fun with such RPs. The thing is, though, they're a bit tricky to pull off. Mainly because you're asking people to make a new character that will never be used outside of your circle/RP. You have to give them enough RP to keep interested/engaged in that character. And in many cases, they'll lose interest in that character due to there only being one place to RP them.
But as I've said, I've still had fun with such RPs. Mainly because I was able to find a group of small but very interested players who were willing to put up with the cons of past-RP and keep coming to my events/RPs.
If you go through with this, best of luck! It has potential to be fun if done right and catches interested people.
If you can keep your head when all about you
Are losing theirs and blaming it on you,
If you can meet with Triumph and Disaster
And treat those two impostors just the same.
Yours is the Earth and everything that's in it,
And - which is more - you'll be a Man, my son.