An Empire normally encompasses many countries within it ruled by the Government of the 'mother country', the country that founded the Empire, via Viceroy's or Governor-Generals.
dynasty
It was conquered briefly by Byzantium and for a longer period of time by the Ottoman empire and included in their territories, but was never a part of a different country in the sense that Kosovo, for example, was.
the roman empire no longer exists. but, no it was not a free country, not even a free empire
german empire and ottoman empire
The Russian empire no longer exists and therefore is no loner in any country.
An empire is a great nation, so to speak, and it controls itself. Italy is the country that once WAS the roman empire, as the capitol of the empire lies in there, if that is what you meant.
Different in different parts of the empire.
An empire is just a large country
It is
Italy is the modern country that was the center of the Roman empire.
The Sassanid Empire was centered in the country now known as Iran.
The Central Powers , as they were collectively known , were German Empire, Austro-Hungarian Empire and the Ottoman Empire (Turkey). The International Boundaries of these empires were different from their modern, post WW(II) counterparts.