The shadows split, all migrated to a continent, and have been observing everything from afar. The actual fact is that Emperor Adam Smith attempted to attack Hellsing. All branches in the Empire were partially and indirectly attacked, in assaults aimed at removing Hellsing from control, something he eventually achieved when he ceased sending official missions to the Guild. From what I understand, it wasn't really something without reason. The royal faction itself expanded significantly when Ethan was announced as the next Emperor, due to the Axilen Family, Ethan's betrothed.
Axlien Yuruzen, a beautiful woman considered one of the most beautiful in the entire kingdom, and her family, Yuruzen, are originally from the eastern continent, or rather, coerced to come to the west with the Emperor's proposals.