The Fallen Royals
All those who are Wizards or Sorcerers are members of the Assembly. Every year children are rounded up and forcefully taken from their homes. Once they have been relocated to the Assembly they no longer have any freedoms until they become a Great One. If they fail the program they are killed so that they do not pose a threat to the Empire. No matter the age of the person, once their ability manifests itself they belong to the Assembly.