Well, the French system seems to turn things on it head. Suddenly a prince is below a count and duke, and they have that crazy "dauphine" or "dolfang" rank, which I don't understand . . .
One thing that often leads to confusion is that there is a significant difference between a
Sovereign Prince, vs. a
Prince of the Blood. Most Americans think of a
Prince of the Blood when they hear the term Prince, which is an unfortunate consequence of the fact that the English language uses the same term for two different concepts (which isn't necessarily true in other languages such as German).
A
Prince of the Blood (German "
Prinz" - from Latin "
Princeps" or "
First Citizen") is a Royal Heir and/or member of a Royal Family.
A
Sovereign Prince (German "Fürst" - from Germanic root meaning
"First") is a proper title of Sovereign Nobility in its own right that has nothing to do with relationship to another sovereign. It typically ranks just above Marquis and just below Duke in the European systems of precedence (
e.g. - The Prince of Monaco), and rules over a sovereign territory known as a
Principality. So the heir of a
Sovereign Prince (i.e.
Fürst) could in fact be a
Prince of the Blood (i.e.
Prinz). See
Fürst:
https://en.wikipedia.org/wiki/Fürst
"Dauphin" is the proper title bestowed upon the heir-apparent to the King of France, just as Prince of Wales is typically conferred upon the heir to the British Throne when he comes of age.
. . . I understand the basic English system, which seems to mirror a lot of Europe. . . .
Actually the English system has some significant differences as compared to the rest of European nobility, particularly concerning who is considered "noble" and/or inherits a title, and who does not. European systems have many more nobles
per capita because in general they consider all children of a noble to be noble (either with or without an inherited title - cf France vs Italy or Germany)
* , whereas in Britain, only the title-holder is noble, and also the heir to the title only when he inherits. The "titles" of the heir and/or junior family members of a British noble are mere "courtesy titles" for
commoners directly related to a Noble. British Marquesses and Dukes are of sufficient prestige that their younger sons (though still considered commoners) are permitted to use the generic title "Lord" before their names (but not their descendants).
* Note that in this sense nobility in the Third Imperium is more like some Continental European systems than the British system and that this is also great CharGen background material for Traveller characters with high Soc: The younger children of Nobles who have both title and connections, but no real power and no real chance to inherit (i.e.Honor/Legacy/Local Nobility). Great reasons to become a Traveller.
Also, in England all Nobles (i.e. "Peers" - Baron or higher) hold their titles directly from the sovereign, whereas in continental systems some noble titles are held thru an intermediary noble.
Every European country/region has its own noble traditions which vary from one system to another; it is not simply a single nobility system with titles translated from one language to another.
France:
https://en.wikipedia.org/wiki/French_nobility
Germany:
https://en.wikipedia.org/wiki/German_nobility
Italy:
https://en.wikipedia.org/wiki/Nobility_of_Italy
http://www.regalis.com/nobletitles.htm
Russia:
https://en.wikipedia.org/wiki/Russian_nobility