These are the forms of address to Royals:
- The King is addressed to as "His Majesty"
- The Queen is addressed to as "Her Majesty"
- Princes (including The Prince of Wales) and Princesses are addressed to as "His/Her Royal Highness".
This forms of address are common for most of European Royalties, with the exception of Principalities, Grand Duchies and (former) Empires.
- In Principalities (such as Monaco or Liechtenstein), the ruler is referred to as "His Serene Highness The Sovereign Prince" or just "His Serene Highness". For example, Prince Albert of Monaco's official style and title is His Serene Highness The Sovereign Prince of Monaco.
Members of the Princely Family (Princes and Princesses) are referred to as "His/Her Serene Highness". For example, Princess Stephanie is "Her Serene Highness The Princess of Monaco".
The Heir Apparent to the Throne is "His Serene Highness The Hereditary Prince".
- In Grand Duchies (such as Luxembourg), the ruler is referred to as "His Royal Highness The Grand Duke". For example, Prince Henri is "His Royal Highness The Grand Duke of Luxembourg".
Members of the Grand Ducal Family (Princes and Princesses) are referred to as "His Royal Highness". For example, Prince Felix is His Royal Highness Prince Felix of Luxembourg.
Heir Apparent to the Throne is referred to as "His Royal Highness The Hereditary Grand Duke of Luxembourg".
- In Empires (such as Japan), the ruler is referred to as "His Imperial Majesty the Emperor" or just "His Imperial Majesty". For example, Emperor Akihito of Japan is referred to "His Imperial Majesty".
The consort of an Emperor is referred to as "Her Imperial Majesty the Empress" or just "Her Imperial Majesty". For example, Empress Michiko of Japan is "Her Imperial Majesty".
Members of the Imperial Family (Princes and Princesses) are referred to as "His/Her Imperial Highness". For example, Prince Fumihito is "His Imperial Highness The Prince Akishino" ("Akishino" is his title, like "Cambridge" is Prince William's).
The Heir Apparent to the Throne is referred to as "His Imperial Highness The Crown Prince". For example, Crown Prince Naruhito is ""His Imperial Highness The Crown Prince".
- In some of the former Empires (such as Austria-Hungary or Russia), titles were somewhat different.
The Austrian ruler was an Emperor ans was referred to as "His Imperial Majesty", however the Russian Emperor also has the title of "Tsar" (roughly, a King); he was also referred to as "His Imperial Majesty". For example, Franz Joseph I of Austria was styled "His Imperial and Royal Apostolic Majesty", while Nicholas II of Russia was "His Imperial Majesty The Emperor and Autocrat of All the Russians".
Members of the Imperial Family of both Russia and Austria-Hungary were Grand Dukes and Duchesses (and not Princes/Princesses) with the style of "His/Her Imperial Highness". For example, Nicholas II's daughters were Their Imperial Highnesses, Grand Duchesses Olga, Tatiana, Maria and Anastasia.
The Heir Apparent to the Austrian Throne was styled as "His Imperial and Royal Highness The Archduke of Austria". For example, Crown Prince Rudolf was "His Imperial and Royal Highness The Archduke, The Crown Prince Austria, Hungary and Bohemia".
The Heir Apparent to the Russian Throne was styled as "His Imperial Highness The Tsarevich". For example, Alexei (Nicholas II's only son) was styled "His Imperial Highness Tsarevich and Grand Duke of Russia".