Royal Highness

Royal Highness is a style, or form of address, used to address or refer to some members of royal families, usually princes or princesses. Kings and their female consorts, as well as queens regnant, are usually styled Majesty.

When used as a direct form of address, spoken or written, it takes the form Your Royal Highness. When used as a third-person reference, it is gender-specific (His Royal Highness or Her Royal Highness, both abbreviated HRH) and in plural, Their Royal Highnesses (TRH).

It is used also for hereditary members of former reigning royal houses.

By the 17th century, all local rulers in Italy adopted the style Highness, which was once used by kings and emperors only. According to Denis Diderot's Encyclopédie, the style of Royal Highness was created on the insistence of Archduke Ferdinand of Austria, Cardinal-Infante of Spain, a younger son of King Philip III of Spain. The archduke was travelling through Italy on his way to the Low Countries and, upon meeting Victor Amadeus I, Duke of Savoy, refused to address him as Highness unless the Duke addressed him as Royal Highness. Thus, the first use of the style Royal Highness was recorded in 1633. Gaston, Duke of Orléans, younger son of King Henry IV of France, encountered the style in Brussels and assumed it himself. His children later used the style, considering it their prerogative as grandchildren of France.

By the 18th century, Royal Highness had become the prevalent style for members of a continental European reigning dynasty whose head bore the hereditary title of king or queen. The titles of family members of non-hereditary rulers (e.g., the Holy Roman Emperor, King of Poland, Princes of Moldavia and Wallachia—and even the kin of the Princes of Orange who held hereditary leadership though not monarchical position in much of the Netherlands, etc.) were less clear, varying until rendered moot in the 19th century. After dissolution of the Holy Roman Empire in 1806, several of Germany's prince-electors and other now sovereign rulers assumed the title of grand duke and with it, for themselves, their eldest sons and consorts, the style of Royal Highness (Baden, Hesse, Mecklenburg, Saxe-Weimar).

The vast majority of African royalty that make use of titles such as prince, chief and sheikh, eschew the attendant styles often encountered in Europe. Even in the cases of the aforesaid titles, they usually only exist as courtesies and may or may not have been recognised by a reigning fons honorum. However, some traditional leaders and their family members use royal styles when acting in their official roles as representatives of sovereign or constituent states, distinguishing their status from others who may use or claim traditional titles.^{[citation needed]}

For example, the Nigerian traditional rulers of the Yoruba are usually styled using the HRH The X of Y method, even though they are confusingly known as kings in English and not the princes that the HRH style usually suggests. The chiefly appellation "Kabiyesi" (lit. 'He/She whose words are beyond question') is likewise used as the equivalent of the HRH and other such styles by this class of royalty when rendering their full titles in the Yoruba language. ^{[citation needed]}

Furthermore, the wives of the king of the Zulu peoples, although all entitled to the title of queen, do not share their husband's style of Majesty but instead are each addressed as Royal Highness, with the possible exception of the great wife.^{[citation needed]}