User blog comment:The Devil's Advocate WP/The Historical Geography of Remnant/@comment-14909251-20140822031956

So, the livestream confirmed the fourth kingdom to be Mistral and the location of Haven. Presumably Sanctum is also located there as a result. I had thought it more likely to be Vacuo, but they did confirm Sun as being from Vacuo. That presumably means Sun is from Vacuo but attends Haven. That would be similar to Weiss attending Beacon despite being from Atlas or Pyrrha attending Beacon despite being from Mistral.