In my post above I've mentioned when exactly china was mentioned zhonghua for the first time a name used till date.it wasntt 1000s of years ago like you claim..medieval dynasties used other names for the region. That's why when we talk about pharaohs of Egypt.. we say ancient egypt.. which is different from current Egypt. We dont say Italy was once a world power.. So there is always a way to describe historic kingdoms and states.the idea of china is different from the western idea of countries. the name "china" (middle kingdom) has been around to refer to the civilization for 1000s of years. each dynasty refers to itself not just by the dynastic name but also that they represent china the civilization. its kind of like how rome had different dynastic ruling families but they all ruled the roman empire and when egypt falls under roman control you would generally say that rome controlled egypt not Julio-Claudian dynasty controlled egypt.