Why are there so many terms for royalty? And I'm talking about generic words like "king", "queen", etc. I seem to remember from my studies that certain terminology was used specifically for Japanese royalty, and other terms were used for foreign royalty of the same status/rank. I also seem to remember hearing that certain terms were related to religion/Buddhism, while others weren't.
From what I understand about "kings" and "emperors", historically there used to be a great distinction: kings ruled kingdoms, which were smaller territories inside of an empire, all of which was (obviously) ruled by the emperor. However, in the present day, I don't think there is such a distinction to most people, as governments have changed greatly over the ages. So the nuances between the terms for "king" and "emperor" (likewise, with "queen" and "empress") seem to overlap a lot.
Here are many of the terms I've used/seen/found for common royalty
King - [王(様)]{おう(さま)}、[国王]{こく・おう}、[君主]{くん・しゅ}、[大王]{だい・おう} 、[大君]{たい・くん}
Emperor - [帝]{みかど}、[皇帝]{こう・てい}、[帝王]{てい・おう}、[大帝]{たい・てい} 、[天子]{てん・し}(様)、[天皇]{てん・のう}、[天王]{てん・のう}
Queen - [女王]{じょ・おう}、[王妃]{おう・ひ}?、[女帝]{じょ・てい}?
Empress - [皇后]{こう・ごう}、[皇太后]{こう・たい・ごう}、[太皇太后]{たい・こう・たい・ごう}、[后]{きさき}、[妃]{きさき}、[王妃]{おう・ひ}、[女帝]{じょ・てい}
Prince - [王子]{おう・じ}、[皇子]{おう・じ}、[皇太子]{こう・たい・し}、[親王]{しん・のう}
Princess - [王女]{おう・じょ}、[皇女]{おう・じょ}、[妃]{ひ} 、[王妃]{おう・ひ}、[親王妃]{しん・のう・ひ}、[内親王]{ない・しん・のう}、[王子妃]{おう・じ・ひ}、[皇太子妃]{こう・たい・し・ひ}、[妃殿下]{ひ・でん・か}、[大君女]{おお・きみ・おんな}、(お)[姫]{ひめ}(様)、[姫御子]{ひめ・み・こ}
Then there are the suffixes [陛下]{へい・か} (Majesty) and [殿下]{でん・か} (Highness)...that you can add to certain ones, but not to all apparently.
Questions
- Why are there so many terms for these generic words?
- If my assumptions from above are correct, which ones are for Japanese royalty and which ones are for foreign royalty?
- " " " ", which ones are religious terms and which are "regular"?
- What are the rules for being able to apply 陛下 or 殿下?
Can someone clear up this mess?