Princes of the Apocalypse
Factions do not play as significant a role in Princes of the Apocalypse as they did in Tyranny of Dragons. If you want to be part of a faction because it fits your character concept, by all means go ahead.
The factions are:
If you choose to have your character be a member of one of these factions, you should consider whether or not you should keep it a secret or share it with the other players/ characters.