Note: the values on this table are based on purchasing power at the time, and related modern purchasing power.  The coins may be worth more to a collector now; I know not.

Emperor / Empress

King / Queen

Royal Prince / Royal Princess

Grand Duke / Grand Duchess

Margrave / Margravine

Count-Palatine / Countess-Palatine

Landgrave / Landgravine

Duke / Duchess

Marquess / Marchioness

Earl, Count, Graf / Countess, Countess, Grafin

Viscount / Viscountess

Baron / Baroness

Baronet / Baronetess

N.B.: I did not write this, and would like to know who did so I can acknowledge them.

Some titles were reserved exclusively for an imperial or royal child. Other times, the child was given an otherwise noble title. The heir of a noble often bears a distinctive style as well.

In English, a prince is the child (and in the male line, a grandchild) of the king or queen-regnant (and in the direct line of succession, the great-grandchildren of the sovereign), and are styled a "royal highness". This nomenclature applies to the children of continental kings and queens-regnant, at least when speaking English.

What distinguishes a style from a title here is unclear. "Dauphin" for the French heir or "Prince of Wales" for the British, while a title, is really more of a style. The same can be said for "Prince [or Princess] of Asturias" for the Spanish heir, but "infante" for a Spanish prince of the blood seems closer to a title as we have been using the term; one may say the same thing about the Habsburg use of "Erzherzog". Title and style for imperial and royal offspring varies from dynasty-to-dynasty. What might be thought of in English as being a non-royal title may in fact be a very royal title in another place.

Most people are aware of the distinction between a royal prince, as with the United Kingdom, and a ruling prince, as with Monaco or Liechtenstein, but are probably confused about who takes precedence over who (a ruling prince usually takes precedence; this is all governed by international protocol). The potential for confusion is also present with grand dukes, as a ruling grand duke would normally outrank the child of a Russian tsar.

The child of a Habsburg emperor was referred to as an archduke or archduchess (Erzherzog or Erzherzogin), a style used by the Habsburgs as far back as the 14th century. It extended to his grandchildren in the direct line of succession.

Absent another specific term, the English term for the heir-apparent to an imperial throne was "Prince [or Princess] Imperial", as with Napoleon III's son, Prince-Imperial Eugene, or the heiress of Dom Pedro II of Brazil, Princess-Imperial Isabel, which in fact was also the form in French and Portuguese.

The German system often makes use of the prefix "Erb" for the heir to a title as with "Erbgraf" whereas the British system prefers using a lesser "courtesy title". William Addams Reitwiesner writes:

"Erb" in German (in this sense) means "hereditary"[. . . .] The oldest son and heir of a Mediatized Count would be an "Erbgraf". The oldest son and heir of a Grand Duke would be an "Erbgroßherzog". And so on. Another way of spelling the title would be "Erb-Prinz" or "Erb-Graf", etc. The wives of these men have equivalent feminine titles, such as"Erbprinzessin", "Erbgräfin", "Erbgroßherzogin", etc. The French form is "prince heredetaire", "comte heredetaire" "grand-duc heredetaire", etc. (toss in accents as appropriate).

In French usage, Prince Albert of Monaco, as heir to Prince Rainier, is a "prince-heredetaire", and Prince Alois, the heir of Hans-Adam of Liechtenstein is, in German usage, an "Erbprinz". "Hereditary Prince" and "Hereditary Grand Duke" sound alien in English, but this is how they must be translated.

This German usage, however, does not extend to royalty; for the Germans, Crown Princess Victoria of Sweden is a "Kronprinzessin" and Prince Willem-Alexander of the Netherlands is a "Kronprinz".

The heir to a French ducal title is sometimes styled "Prince of Suchandsuch", but this is more a "courtesy title" (see François Velde's comments under "Prince"), and roughly corresponds to the British practice of the heir to a peerage using a lesser title held by the actual peer, as with the marquessate of Blandford for the Dukes of Marlborough.

In the Russian system, "grand duke" is the English term for the son of a tsar, a translation for "velikiy knyaz" (which might be better translated as "great [or grand] prince"). For a grand duchess, the Russian term is "velikiy knyazhna" if unmarried, "velikiy knyagina" if married. This is a title that was used by the Grand Dukes of Muscovy. In German, this is termed Großfürst or Großfürstin (vs. "Großherzog" = Grand Duke). This is considered equivalent to archduke or archduchess, but needs to be distinguished from sovereign grand dukes (as with Luxembourg). Generically, the son of a Russian tsar was termed a "tsarevich", a daughter "tsarovna". "Tsesarevich" or "cesarevich" has been stated to be a title reserved for the eldest son of the tsar.

The son of a Spanish king or queen-regnant is termed an infante, a daughter an infanta, in distinction to "principe" or "princesa". The king or queen-regnant's heir, however, is always styled Prince or Princess of Asturias (Principe de Asturias). A Princess of Asturias can be "demoted" to mere infanta by the advent of a baby brother; the wife of the Prince of Asturias, however, is styled the Princess of Asturias.