[2][3] In English usage, the terms Highness, Grace and Majesty were all used as honorific styles of kings, queens and princes of the blood until the time of James I of England.
[1] Thus in documents relating to the reign of Henry VIII of England, all three styles are used indiscriminately; an example is the king's judgment against Dr. Edward Crome (d. 1562), quoted, from the Lord Chamberlains' books, ser.
[3] At the conclusion of the Congress of Vienna in 1815, His/Her Highness (abbreviated HH), became prevalent for reigning dukes and members of their dynasties in Germany (e.g., Anhalt, Brunswick, Nassau, the three Ernestine duchies of Saxe-Coburg and Gotha, Saxe-Meiningen, and Saxe-Altenburg, as well as Schleswig-Holstein); for cadets of some German grand ducal houses (e.g., Hesse, Mecklenburg-Schwerin, Mecklenburg-Strelitz, Oldenburg, Saxe-Weimar-Eisenach); and cadet members of some imperial or royal families (e.g., Bavaria, Denmark, the Netherlands, Norway, Portugal, Prussia, Russia, Yugoslavia).
The Almanach de Gotha and Burke's Peerage continued to ascribe Highness to members of deposed dynasties of ducal rank.
Among the nobility, the Almanach de Gotha notes that Highness was accorded to the heads of the families of Murat (a royal dynasty during the Napoleonic era), Hohenberg, Teck and all members of the House of Ligne.
While "Highness" (Hoheit) was used for rulers of German duchies, the sovereign Dukes of Modena and of Parma were heads of cadet branches of ruling dynasties of higher rank.
[9] In Afghanistan the title Jalalat Mahab is used for Sardars, or Princes of the former Muhammadzai dynasty, who are descendants of the Afghan Emir Payindah Muhammad Khan Barakzai.
[10][11] Prince Daoud Khan, a member of the Telai cadet branch and Cousin of the last Afghan King Zahir Shah, acting as prime minister under his cousin held the address Jalalat Mahab Aali Qadr Sardari Alaa (English His Honorable Highness the sublime Prince) during his term as Prime Minister.
In Saudi Arabia, all members of the royal family have the title of Emir (Prince) but sons, daughters, patrilineal granddaughters and grandsons of Ibn Saud are referred to by the style "His Royal Highness" (HRH), differing from those belonging to the cadet branches who are styled as "His/Her Highness" (HH), and in addition to that a reigning king has the title of Custodian of the Two Holy Mosques.
[20] Very rarely, the style of Highness or variations thereof have been used by non-monarchical heads of state, particularly before the 20th century, and often in cases where the distinction between monarchy and republic was blurred.
In Spain, Manuel Godoy, who twice served as Prime Minister from 1792 to 1797 and from 1801 to 1808, was granted the style of Most Serene Highness (Su Alteza Serenísima) in 1807 by King Charles IV.
Espartero had previously declined an offer to the throne following the Spanish Revolution of 1868, which instead went to the Italian Amadeo of Savoy, who in turn bestowed the royal princedom on him.
Selva Alegre's pseudo-monarchical government, which was formed following Napoleon's invasion of Spain in 1808 and lasted for a mere seventy-five days, was considered by both contemporaries and later historians to be a thinly-disguised effort to establish a "Kingdom of Quito"; Selva dressed himself in regal vestments, bestowed honours on citizens, and instituted the National Order of San Lorenzo (which was much later revived by Ecuadorian President Camilo Ponce Enríquez in 1959).
[22] Antonio López de Santa Anna, enjoyed the official style of Most Serene Highness during his eleventh and final tenure as President of Mexico for life from 1853 until his deposal in 1855.
[24] Adams' efforts were met with widespread derision and perplexion; Thomas Jefferson called them "the most superlatively ridiculous thing I ever heard of", while Benjamin Franklin considered it "absolutely mad".
Regardless of the official traditions in the various colonial empires, the style is evidently used to render, often merely informally, various somewhat analogous titles in non-western cultures, regardless whether there is an actual linguistic and/or historical link.