There are Princes and Princesses, and then there are Princes and Princesses. Some are Royal or more, some are not. The problem lies in geography. Depending on where the title came from, the title of Prince does not mean the same thing. The puzzle can be solved given some knowledge of geography and history, and quite some of the muddle derived from translating foreign titles into English.
Everybody loves the stories in which the Princess gets her Prince. But Princes and Princesses may be deceiving you with their very titles. The title of Prince does not necessarily mean a Royal Highness, and a Royal Highness may be hidden behind another title. There is system to the madness though, but it needs explaining. I’ll have to keep my explanation confined to European titles as otherwise this article will really become a total mess.
Let’s start at the top and work the way downwards as we go. To decide where the top is, keep an eye out for the accolades (in order of precedence) of HIH (His/Her Imperial Highness), HRH (His/Her Royal Highness), and HSH (His/Her Serene Highness). The accolade HH (His Holiness) is used for religious leaders like the Pope and we would expect no Princes or Princesses to descend from him, though Cardinals are often colloquially referred to as the Princes of The Church. The Pope, by the way, is a Serene Highness as well in his function as Prince of Vatican State.
HIH is reserved for the Imperial houses of Austria (Habsburg), France (Bonaparte), and Russia (Romanov), all three of which are not in power anymore. HRH is used for ruling and formerly ruling Royal families. Any descendant of one of these families produces offspring that qualifies for Princes and Princesses as we understand it from fairy tales. Just to muddy the water: Ruling and formerly ruling Grand Dukes and Dukes count as Royalty and rate a HRH. HSH is used for offspring from ruling and formerly ruling families of lower rank. The descendants of these serene families are all automatically titled as Prince or Princess.
In that sense, the Princely houses of Monaco and Liechtenstein produce Princes and Princesses by birth rather than having the title bestowed at birth by the sovereign. This also means that if one of these Princes (not necessarily the ruling Prince himself) marries, his wife automatically accrues the title of Princess. Charlene Wittstock has therefore become a Princess, albeit a HSH one.
Royal (HRH) and Imperial (HIH) titles of Prince or Princess and the accolades of Royal or Imperial Highness on the other hand are handed out by the ruling or titular monarch; this means that the wife of such a Prince does not automatically accrue either the title of Princess or the accolade but receives any titles from the sovereign. In that sense, Maxima of the Netherlands, Letizia of Spain, Mary of Denmark, Mette-Marit of Norway, and Daniel of Sweden have all been handed title and accolade, whereas Catherine has been handed only the accolade of HRH without the Princess.
The Prince and Princess muddle is due to a translation problem. In German, there are two distinct titles for two very distinct grades of nobility. Prinz (as in Prince) is used the same way as in English for HRH upwards. The real trouble lies in the title of Fürst (translated into English as Prince). It is in fact the lowest of German Peerages on a par with the British Baron. The German Barons (Baron, Freiherr, Freier) are on a par with a Baronet and rate a Sir and not a Lord. German Counts (Graf) come in two classes: Ruling counts were part of the peerage, titular counts weren't. The other titles like (in order of precedence) Prince Elector (Kurfürst), Duke (Herzog), Landgrave (Landgraf), Count Palatine (Pfalzgraf), and Margrave (Markgraf) all were ranked higher than the Fürst. This brings us full circle back to Monaco and Liechtenstein which fall into the latter category.
You might have noticed a few omissions; the title of Archduke is only used for members of the Habsburg family, they are therefore always addressed as HI&RH (His/Her Imperial and Royal Highness). The Grand Duke of Luxembourg is addressed as Royal Highness, as are the sons and daughters of the Grand Duke; and the Grand Dukes of Russia are reserved for the Romanov family and always rate a HIH. French titles are easier to adapt as the system corresponds mostly to the Anglo-Saxon usage, while Italian titles are mostly in line with the German system.
As German titles became part of the family name in 1918, you don’t have to contend with all the Princes and Princesses descended from noble families anymore; the son of a Margrave becomes a Margrave by dint of family name and not a Prince. There remain the Princes (Fürst) and their descendants, though, which are constantly overrated in the Anglo-Saxon world; such a Prince is the Prince of Anhalt, infamous husband to Zsazsa Gabor (who wasn't born a Prince but bought his title through adoption from an impoverished Princess of Anhalt). If you want to be super correct, you might still use the title Prince for a son of the higher peerage (if you know for sure that the father is still alive), or in certain instances the form of Hereditary Prince for the oldest son (of a life father). I wouldn't recommend it if you aren't intimately acquainted with the family; under which circumstances you’d probably use first names anyhow. Whatever they are, fairy tale Princes they aren't.
If you haven’t wiggled a knot into your tongue while reading this, it’s all rather a lot of fun; as long as you don’t take it too seriously. If you really want to boggle your brain, though, you might want to know that HRH in a ruling house are full accolades, while the use of the same for members of a deposed Royal family are courtesy accolades. But not all deposed Royal families are down to courtesy accolades as the Greek Royal family usually gets a full accolade from the ruling monarch of Denmark under Danish law. Confused?
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