~ Happy reading ~
That's an interesting one with a great idea.
Voldemort won the first war (the one which couses the death of Lily and James) and rules magical Britain now although there is a resistance.
There are four castes:
And that's just the setting.
Harry was a Menial, became a Courtesan in training at his 13th birthday, a full Courtesan at his 16th birthday bought by Rabastan Lestrange until his unsetteled magic drove him straight into Voldemorts property.
Right now I'm reading about the first members of the Order of the Phoenix (working from the underground against Voldemort).
I really like it so far.