The term is now borne as a title mainly in Asia, Scandinavia, and the Middle East; but it may also be used generically to refer to the person or position of the heir apparent in other kingdoms. However, heirs apparent to non-imperial and non-royal monarchies (i.e., wherein the hereditary sovereign holds a title below that of king/queen, e.g., grand duke or prince), crown prince is not used as a title, although it is sometimes used as a synonym for heir apparent.
In Europe, where primogeniture governs succession to all monarchies except those of the Papacy and Andorra, the eldest son (Spain) or eldest child (Belgium, Denmark, the Netherlands, Norway, Sweden, and the United Kingdom) of the current monarch fills the role of crown prince or princess, depending upon whether females of the dynasty enjoy personal succession rights. The eldest living child of a monarch is sometimes not the heir apparent or crown prince, because that position can be held by a descendant of a deceased older child who, by "right of representation", inherits the same place in the line of succession that would be held by the ancestor if he or she were still living (e.g., Carl Gustaf, Duke of Jämtland, was Crown Prince of Sweden from 1950 to 1973, as the senior grandson by male primogeniture of King Gustaf VI Adolf of Sweden, although the former Prince Sigvard, Duke of Uppland, was Gustaf VI Adolf's eldest living son, and Prince Bertil, Duke of Halland, his eldest living dynastic son during those years).
In some monarchies, those of the Middle East for example, in which primogeniture is not the decisive factor in dynastic succession, a person may not possess the title or status of crown prince by right of birth, but may obtain (and lose) it as a result of an official designation made on some other legal or traditional basis, e.g., former Crown Prince Hassan bin Talal of Jordan.
Compare heir apparent and heir presumptive. In Scandinavian kingdoms, the heir presumptive to the crown may hold a different title than the heir apparent: Hereditary Prince (German: Erbprinz, French: prince héréditaire). It is also the title borne by the heir apparent of Liechtenstein, as well as the heir apparent or presumptive of Monaco. In Luxembourg, the heir apparent bears the title of Hereditary Grand Duke (German: Erbgroßherzog, Luxembourgish: Ierfgroussherzog); along with Hereditary Prince, it was also the title borne by the heirs apparent to the thrones of the grand duchies, sovereign duchies and principalities, and of mediatized princely families in the German monarchies abolished in 1918.
Christian/Western traditional titles
Many monarchies use or did use unique titles for their heirs apparent, often of historical origin:
- Dauphin (Kingdom of France)
- Duke of Brabant (Belgium)
- Duke of Braganza (Kingdom of Portugal)
- Duke of Cornwall (Kingdom of England)
- Duke of Rothesay (Kingdom of Scotland), currently used by the Prince of Wales in place of his Welsh title when in Scotland
- Grand Prince (Grand Duchy of Tuscany)
- Margrave of Moravia (Kingdom of Bohemia)
- Prince of Asturias (Castile & Spain)
- Prince of Girona (Aragon & Spain)
- Prince Imperial (Empire of Brazil, Second French Empire, and Empire of Mexico)
- Prince of Orange (Netherlands), whether or not the equivalent title is held by the spouse of the titleholder is decided by the Dutch parliament (e.g., Queen Máxima of the Netherlands was never titled Princess of Orange by marriage for this reason)
- Prince of Piedmont (Kingdom of Sardinia, and then Kingdom of Italy, when it was alternated with Prince of Naples)
- Prince Royal (France in 1789–91 and the July Monarchy, and Portugal since 1815)
- Prince of Turnovo (Kingdom of Bulgaria)
- Prince of Viana (Navarre & Spain)
- Rex iunior (Kingdom of Hungary), lit. junior king as he was crowned during the life of the incumbent king
- Tsesarevich (Russia)
Some monarchies have used (although not always de jure) a territorial title for heirs apparent which, though often perceived as a crown princely title, is not automatically hereditary. It generally requires a specific conferral by the sovereign, which may be withheld.
Current and past titles in this category include:
- Caesar or Kaisar (Roman and early Byzantine Empires) in honor of Gaius Julius, distinguished from the senior Augustus
- Symbasileus (late Byzantine Empire), lit. co-emperor but still distinguished from the senior who was addressed as Autocrator
- Aetheling (Anglo-Saxon England) and edling (Welsh kingdoms), lit. of the royal family
- Duke of Estonia and Lolland (Denmark; during, at least, reigns of Christopher II and Valdemar IV)
- Prince of Norway (Denmark-Norway); in 15th-19th centuries
- Duke of Valentinois, used by several heirs to the Monégasque throne
- Prince of Wales (England, Great Britain, United Kingdom)
- King of the Romans (Holy Roman Empire) - an elective, rather than an inherited title, for the designated successor—usually the son, but sometimes the brother—of the Emperor
- King of Rome (First French Empire)
- Duke of Sparta (Kingdom of Greece); used briefly, within Greece, only by Prince Constantine, during the reign of his father King George I
- Marquess of Baux : used by several heirs to the Monégasque throne
- Prince of Brazil (title of the Portuguese heir from 1645 to 1815)
- Duke of Scania (Sweden during the time when Magnus IV of Sweden also was King of Terra Scania)
- Prince of Ani (Kingdom of West Armenia)
- Prince of Alba Iulia (Kingdom of Romania)
- Grand Voivode of Grahovo (Kingdom of Montenegro)
- Prince of Venice (see Prince Eugène de Beauharnais); for the heir presumptive to Napoleon I in his Kingdom of Italy
- Duke of Calabria (Kingdom of Naples and Kingdom of the Two Sicilies); prior to the accession of King Robert the title of the Neapolitan heir was Prince of Salerno
'Crown Prince' as a title for an heir apparent used today
Currently, the following states use the title "Crown Prince" (or "Crown Princess") as the title for the heirs apparent to their thrones:
- Bahrain - Crown Prince Salman bin Hamad bin Isa Al Khalifa
- Brunei - Crown Prince Al-Muhtadee Billah
- Denmark - Crown Prince Frederik, Count of Montpezat
- Japan - Crown Prince Naruhito
- Jordan - Crown Prince Hussein
- Kuwait - Nawaf Al-Ahmad Al-Jaber Al-Sabah
- Morocco - Crown Prince Moulay Hassan
- Norway - Crown Prince Haakon
- Saudi Arabia - Crown Prince Muhammad bin Nayef
- Swaziland - (position of Crown Prince currently vacant)
- Sweden - Crown Princess Victoria, Duchess of Västergötland
- Thailand - Crown Prince Maha Vajiralongkorn
- Tonga - Crown Prince Tupoutoʻa ʻUlukalala
- United Arab Emirates: each of the constituent emirates of the U.A.E. uses the title of 'Crown Prince' for their heirs apparent:
- Abu Dhabi - Crown Prince Mohammed bin Zayed Al Nahyan
- Dubai - Crown Prince Hamdan bin Mohammed bin Rashid Al Maktoum
- Fujairah - Crown Prince Mohammed bin Hamad bin Mohammed Al Sharqi
- Ajman - Crown Prince Ammar bin Humaid Al Nuaimi
- Ras Al-Khamiah - Crown Prince Muhammed bin Saud bin Saqr Al Qasimi
- Sharjah - Crown Prince Sultan Bin Mohammed Bin Sultan Al Qasimi
- Umm al-Quwain - Crown Prince Rashid bin Saud bin Rashid Al Mua'lla
In addition; the following heirs apparent to deposed monarchies use the title of Crown Prince as a title used by international courtesy:
- Ahmad Shah Khan, Crown Prince of Afghanistan
- Pavlos, Crown Prince of Greece.
- Reza Pahlavi, Crown Prince of Iran.
- Paras, Crown Prince of Nepal
- Alexander, Crown Prince of Yugoslavia.
Other specific traditions
Persia (Iran), Pahlavi dynasty and Qajar dynasty, the full style was Vala Hazrat-i-Humayun Vali Ahd, Shahzada (given name), (in Persian: والاحضرت همایون ولایتعهد) i.e. His August Imperial Highness the Heir Apparent, Prince ...;
- the above component vali ahd (or Velayat Ahd) meaning 'successor by virtue of a covenant' (or various forms and etymological derivations) was adopted by many oriental monarchies, even some non-Muslim, e.g. Walet as alternative title for the Nepali (Hindu) royal heir apparent; first used Crown Prince Trailokya in the middle of the nineteenth century, taken from the Mughal title 'Vali Ahd'
Hindu tradition (Indian subcontinent):
- Yuvaraja was part of the full title in many princely states of India, e.g.
- in Jammu & Kashmir, the heir apparent was styled Maharaj Kumar Shri Yuvaraj (personal name) Singhji Bahadur
- Nepal, where the King was styled Maharajadhiraja:
- the heir apparent was styled: Sri Sri Sri Sri Sri Yuvarajadhiraj ('Young King of Kings', i.e. Crown Prince) (personal name) Bir Bikram Shah Deva;
- the eldest son of the heir apparent was styled: Sri Sri Sri Sri Sri Nava Yuvaraj ('Young Crown Prince') (personal name) Bir Bikram Shah Deva
East Asian traditions:
- The cognates of Chinese Huang Taizi (皇太子, "Great Imperial Son") - if a son of the reigning emperor, and Huang Taisun (皇太孫, Great Imperial Grandson) - if a grandson of the emperor:
|if the heir apparent is a:||son||grandson|
|Chinese||Huang Taizi||Huang Taisun|
|Korean||Hwangtaeja (황태자)||Hwangtaeson (황태손)|
|Vietnamese||Hoàng Thái Tử||Hoàng Thái Tôn|
- During the Joseon Dynasty in Korea, the crown prince was referred as Dong-gung(동궁, 東宮) due to the location of his residence from the main palace; or wangseja (王世子 왕세자). He was not necessarily the first-born son, wonja (元子 원자).
Southeast Asian traditions:
- Siam Makutrajakuman (สยามมกุฎราชกุมาร) in Thailand since 1886.
- Krom Phrarajawangboworn Sathanmongkol or Phra Maha Uparaja or commonly called Wang Na (or Front Palace) in Thailand prior to 1886.
- Kanjeng Gusti Pangeran Adipati Anom in Yogyakarta sultanate and Surakarta, Indonesia.
- Raja Muda or Tengku Mahkota in the Malay sultanates of Malaysia.
- Pengiran Muda Mahkota in Brunei
Equivalents in other cultures:
- Caesar (title) (since the tetrarchy) and Consors imperii
- Princeps iuventutis
- Prince of the blood
- "Crown Prince Party" of the People's Republic of China
- List of heirs apparent