Thanks LuDongBin Seeing the graphic you found (which does indeed show the change of territories to the succeeding Tang [hit me as could be labelled a spoiler by some...]) inspired me to do a search too, what do think of :
$this->handle_bbcode_img_match('https://upload.wikimedia.org/wikipedia/commons/thumb/a/ac/China%2C_610.svg/1000px-China%2C_610.svg.png')
Is A.D 610 an especially apt year for starting this story ?