I suppose it would fall somewhere between the decline of the Sui dynasty and the buildup of the Tang dynasty. It closely follows the Three Departments and Six Ministries model of government, but there are more ministries. At the moment, I'm still deciding over specifics, so this might change a bit. However, that's only in regards to government structure. Do you have a favorite time period for art and dress? XD I'm not going to force any guys that join the RP to have topknots (they can have them if they want... of course)!