Ancient monarchs called themselves King of the Persians or Scythians, regarding themselve merely as the leaders of men. Today's monarchs more shrewdly call themselves King of France or England. By holding the land, they are sure of the inhabitants.
Gist of Idea
Ancient monarchs were kings of peoples; modern monarchs more cleverly rule a land
Jean-Jacques Rousseau (The Social Contract (tr Cress) , I.9)
This matches the Germans being earlier defined by speaking the language, and now defined by a territory. It is more to do with the rise of the modern state than to do with the shrewdness of the monarchs.
Rousseau,Jean-Jacques: 'The Basic Political Writings', ed/tr. Cress,Donald A. [Hackett 1987], p.152