Another belated drive-by comment: I was struck, when researching English history, by the way that the process used to happen almost in reverse, with monarchs/aristocracy/etc being referred to by the names of the lands they ruled. Elizabeth I was "England," the Duke of Norfolk was "Norfolk," etc. That could be seen as mapping the realms to the specific individuals (which would make sense according to the thought of the time), while the modern usage might be mapping a large group of people to the nations they serve.