Drawn after "The Divisions of China, 535-560 A.D." Albert Herrmann (1935) History and Commercial Atlas of China. Harvard Press.
<a href="//commons.wikimedia.org/wiki/User:Ian_Kiu" title="User:Ian Kiu">Ian Kiu</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>