I was at a loss when I was asked recently by my grand-daughter who is a school girl about the difference between Emperor and King. She asked me why Great Britain has King and Queen, while Germany and Russia had the Emperors, and France had both Kings and Emperors. All what I could tell her was, ‘you’d better study by yourself, don’t count on others.”
Being sorry for her, I checked dictionaries at hand, but was simply confounded.
For instance, OALD defines:
Emperor: the ruler of empire.
Empire: a group of countries that are controlled by one ruler / government.
King: the (male) ruler of an independent state / country that has a royal family.
Kingdom: a country ruled by a king (or queen).
The difference seems to be;
- King has a royal family.
- Empire is a group of countries (under one ruler).
But emperors have royal families as well, and Japan that has had the emperors for a millennium has been a single country (except the imperialism era of 1910–1945), and China who had emperors wasn’t a group of countries.
Can you tell me what is or are the essential (functional and institutional) difference(s) between Emperor and King so that I can give a belated answer to my grand-daughter?