in chapter 243, when shin gains the rank of 1000 men commander, he also gets his rank in nobility raised. does someone knows how many ranks there are, which rank shin is now and what benefits each rank holds?
It follows the 20 something Noble ranks that defined Chinese aristocracy during the period to which this manga is set. The author tries to stick to the actual history as is in this case.
The highest rank is sovereign and lowest is slave.